Evaluation of the Corrosion Durability of Steel Systems for

Transcription

INTRODUCTION
The Strategic Alliance for Steel Fuel Tanks (SASFT) was organized in
2000 by the American Iron and Steel Institute (AISI) to bring together
the diverse business disciplines involved in designing, manufacturing
and supplying steel fuel tanks in the automotive market. SASFT has
evolved to become an international alliance of 32 companies having a
common interest in the development, optimization and application of
fuel tanks for automobiles. The full members are shown on the back
page of this report, along with those automobile OEM Associate
members who participate in an advisory capacity.
The corrosion study reported herein was organized, managed and
written by the Corrosion Evaluation Team of SASFT. The
participating companies and individual representatives of the
Corrosion Evaluation Team were as follows:
For More Information on SASFT:
Visit:
www.sasft.org
Contact: Peter Mould
Program Manager
001 810.225.8250
[email protected]
For More Information on AISI:
Visit:
www.autosteel.org
Contact: Ronald Krupitzer
Senior Director
001 248.945.4761
[email protected]
Arcelor
Laurent Dallemagne
Gerd Schwerzel
Michel Luciani
Art Coleman
Corus
Terry Burton
Dofasco, Inc.
Rick Daley
Harley Davidson
Sue Jokela
International Steel Group
Steve Jones
Stavros Fountoulakis
JFE Steel
Setsuo Mega
Tetsuo Sakiyama
Toshihiro Kikuchi
Martinrea International
Ray Sheffield
National Steel Corp.
Bruce Hartley
Nippon Steel
Shinichi Itonaga
The Magni Group
Doug Paul (Chairman)
Greg Tarrance
ThyssenKrupp Stahl
Wilhelm Warnecke
United States Steel Corp.
Matt McCosby
SASFT's global reach recognizes that different business and
technological issues impact the type of fuel tanks produced in different
geographic regions. By understanding these issues rational, optimized
approaches can be fully deployed for steel fuel tanks.
Evaluation of the Corrosion Durability of Steel Systems for Automobile Fuel Tanks
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TABLE OF CONTENTS
Introduction ....................................................................................................................................................................................... 2
Executive Summary .......................................................................................................................................................................... 4
Genesis of the Corrosion Study ....................................................................................................................................................... 6
Historical Assessment of the Corrosion Resistance of Steels for Automobile Fuel Tanks ...................................................... 7
Scope and Objectives of the Corrosion Study ................................................................................................................................ 8
General Considerations of Corrosion Testing for the SASFT Study
Test approach and input from automakers ................................................................................................................................... 9
Exposure times and life equivalencies ........................................................................................................................................... 9
Steel system candidates for corrosion testing ............................................................................................................................. 10
Criterion for failure ......................................................................................................................................................................... 11
Independent testing ........................................................................................................................................................................ 11
Experimental Procedures Adopted for the Corrosion Study
Test methods and corrosion evaluation procedures .................................................................................................................. 13
- Neutral Salt Spray (ASTM B117)
- Cyclic Corrosion Resistance Test (SAE J2334)
- Test validation specimens
- Gravelometer
- Fuel Test
Configuration and Preparation of Test specimens ..................................................................................................................... 14
- Specimens for External Testing (Neutral Salt Spray and Cyclic tests)
- Specimens for Internal Testing (Fuel tests)
- Fabrication of Test Specimens
Evaluation Procedures ................................................................................................................................................................... 18
- Neutral Salt Spray test
- Cyclic Corrosion test
- Gravelometer test
- Fuel test
Test materials (steel systems) ........................................................................................................................................................ 20
Results and Discussion
External Neutral Salt Spray test (ASTM B117) ............................................................................................................................ 22
- Qualitative Evaluation after 2000 hours
- Quantitative Evaluation
External Cyclic Corrosion Resistance Test (J2334) ..................................................................................................................... 25
- Qualitative Evaluation after 80, 120 and 160 cycles
Internal Fuel Test ............................................................................................................................................................................ 32
- Qualitative Evaluation
Summary of Results ........................................................................................................................................................................ 37
Conclusions ..................................................................................................................................................................................... 43
References and Notes ..................................................................................................................................................................... 44
Acknowledgments .......................................................................................................................................................................... 45
List of Attachments ........................................................................................................................................................................ 46
- Photo Library (file names, photo and specimen identifications) .................................................................................... 48
- Appendixes ............................................................................................................................................................................ 57
- Listing 1: Neutral Salt Spray ............................................................................................................................................ 48
- Listing 2: Cyclic Corrosion ............................................................................................................................................... 50
- Listing 3: Fuel Test ............................................................................................................................................................. 54
- SASFT Members ..................................................................................................................................................................... 90
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EXECUTIVE SUMMARY
In recent years, automakers have questioned the corrosion durability of steel for automotive fuel tanks. To
address this concern, the Strategic Alliance for Steel Fuel Tanks (SASFT), an international group of 32
companies representing steel fuel tank manufacturers, suppliers and steel companies, and organized by the
American Iron and Steel Institute (AISI), sponsored a comprehensive study of the corrosion resistance of
several commercially available steel systems.
The objective of the corrosion study was to assess the resistance of selected steels to the severe external
corrosion conditions experienced by automobile fuel tanks and to the potential for internal corrosion (inside
the fuel tank) posed by aggressive alcohol-containing fuels. It was particularly important to assess the
ability of the steels to meet the 15-year durability requirements set by the California Air Resources Board
(CARB) for low emission vehicles.
In recent years, various new steel "systems" have been developed by the worldwide steel industry for
automobile fuel tanks. (The term "system" denotes a unique approach for resisting corrosion, such as
special coatings, and/or special steel alloys.) Twelve of these systems were initially selected for this study
by SASFT. However, 2 post-painted systems were subsequently withdrawn because of inadequate paint
film thicknesses. Thus, 10 steel systems completed the testing in this study. The steels selected were
representative of the three principal categories of steel tank manufacturing approaches currently used
throughout the world; these are:

Pre-painted steels: Tanks are manufactured from steel coils which have been pre-painted on
both sides of the steel sheet. The assembled tanks then receive limited, local post-painting on
the outer surfaces at the weld areas.
Post-painted steels: Steel tanks are fabricated from unpainted steel coils. The tanks are then
post-painted completely on the outer tank surfaces.
Bare steels: Bare steels (such as stainless steels) where no pre- or post-painting is used.
Test specimens were specially designed to reflect the unique corrosion conditions of a fuel tank affixed to a
vehicle. The External Corrosion specimens incorporated a scribe line to simulate a scratch exposing the bare
steel, a dome simulating forming strains, a weld flange with a clip to simulate a crevice corrosion site, and an
area exposed to gravel impact which simulates stone chipping conditions.
To assess the External Corrosion resistance, two simulative bench-scale procedures were used: the Neutral
Salt Spray test (ASTM B117) with exposures up to 2000 hours and the Cyclic Corrosion test (SAE J2334) with
exposures up to 120 and 160 cycles. The latter exposures were selected to simulate road lives of 15 years and
20 years, respectively. Perforation was adopted as the criterion for failure. However, the progress of
corrosion was assessed qualitatively by visual observation and photographs, and quantitatively by measuring
pit depths over the entire specimen, assessing coating integrity by creepback at the scribe line and chip ratings
after gravel impact.
To determine the Internal Corrosion resistance, deep drawn cups and flat lids were assembled to contain
an aggressive fuel (CE10A). (This fuel was chosen on the basis of prior experience by automakers and their
recommendations to SASFT.) The fuel- cup assembly was sealed by an inert gasket and clamping rings. The
fuel cup assemblies were held at 45 ± 2°C for 39 weeks to simulate a 15-year tank exposure. The fuel was
changed every four weeks to simulate repeated fuel tank filling and to replenish contaminant ions and
minimize oxygen depletion (per the test fluid specifications of SAE J1747). The extent of corrosion was
evaluated qualitatively by recording the extent and location of corrosion and quantitatively by weight
changes and pit depths.
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EXECUTIVE SUMMARY (Cont.)
The following key findings were obtained from the two External Corrosion tests:
No perforation was observed at any location for any of the steel systems. Corrosion pit depths were
observed at isolated locations for only two steels. Additionally, the maximum depths of the pits
were only 0.2 to 0.4mm, representing about 20 to 40 percent of the original steel thickness.
The extent of corrosion (red and white rusting) varied by location on the specimen and from
material to material. For the most part, slight (<15% surface area) or moderate (15-30%) rusting
was observed, and pronounced rusting (>30%) occurred only in a few instances. The variations in
the extent of corrosion were not of such significance to rate one steel system over another.
The integrity of the paint systems, as indicated by resistance to gravel impact and creepback, varied in
proportion to the thickness of the paint films.
Those pre-painted systems having thin organic resin films (about 9µm thick) and one stainless
steel, having an inorganic paint film (about 17µm thick), showed small amounts of paint chip loss
after initial gravel impacts. However, subsequent gravel impacts did not progressively increase
the paint chip loss.
Those post-painted systems having thick coatings (up to 370µm) showed no paint chip loss or
creepback at the scribe line.
Steels with thin post-paint films (20 to 150 m) showed adhesion loss and creepback proportional to
the coating thicknesses. This suggests that the paint integrity of these systems could be increased by
using thicker paint films.
The results for the Internal Corrosion (Fuel) tests showed:
Very minor weight losses (less than 0.13%) for all the specimens after the maximum 39-week
exposure.
Some variations in the extent of a white residue occurred between the samples. The white residue
occurred primarily at the liquid-vapor interface. However, the residue was insufficient to conduct any
post exposure analysis.
No perforation occurred and, in fact, no pits deeper than 0.1mm were observed in any of the cups
or lids.
The results demonstrate that all of the steel systems tested in this bench-scale study will resist external and
internal corrosion (in the severe environments that can be experienced by automotive fuel tanks) for up to 20
years. Thus, it is fully expected that the systems will meet the 15-year durability requirements of CARB. It
is recommended that automakers conduct their own tests (including proving ground tests) to validate the
on-vehicle corrosion durability of the steel systems tested herein.
The selection of one steel system over another will depend on factors other than the corrosion resistance,
such as the manufacturing approach favored by the automaker, material and manufacturing costs,
inherent manufacturability (forming and welding), and available manufacturing equipment. Because these
factors are beyond the scope of this study, it is recommended that automakers contact the suppliers of the
specific steel systems.
The guidance and encouragement received from many automakers during the development of the testing
methodology used in this study is gratefully acknowledged.
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GENESIS OF THE CORROSION STUDY
Steel has been the material of choice globally for automobile fuel tanks for the majority of the 20th century.
The steel used primarily has been low carbon steel, coated with a terne alloy (90% lead and 10% tin). The
terne coating was an effective barrier to potential corrosion from the external environment (road salts, stone
chipping, etc.) and the internal environment (gasoline and diesel fuels). Despite the long, successful history of
terne-coated steel fuel tanks, the following business and technical issues have caused a significant change in
fuel tank materials and in the type of steel for the steel option.
Legislative pressures to reduce heavy metals in the manufacturing and recycling streams. This
caused automakers to move away from lead-containing materials including terne-coated sheet steel.
Automaker requirements for increased durability as a result of more severe corrosion environments
such as increased usage of road salts as well as the emergence of flexible fuels.
Emergence and growth of highly durable HDPE plastic fuel tanks.
Legislative regulations on automobile evaporative emissions to reduce air pollution.
Several national government agencies (such as U.S. EPA and equivalent organizations in Europe
and Japan) have set maximum emission levels for light vehicles (cars and light trucks). In the
U.S.A., California's Air Resources Board (CARB) has set very strict emission levels to reduce
California's acute air pollution problems. Because of steel's inherent impermeability to fuels, steel
tanks are well-suited to meeting California's stringent evaporative emission standards. However, an
additional requirement by CARB, for 15-year durability of the exhaust emission system and the
entire fuel system raises the issue of the corrosion resistance of the materials used.
In response to the demand for more durable steels for fuel systems, steel makers worldwide developed a
variety of new steel "systems," where "system" describes a compound approach to achieving good corrosion
resistance while retaining good manufacturability (forming and welding) and tank performance. Such
systems include, metallic coated low carbon steels with sophisticated pre-paints and post-paints, as well as
stainless steels (such as austenitic 304L and ferritic 436L steels), and are commercially available.
The durability of the commercially available steel systems has been assessed by steel companies and users
alike. However, a variety of corrosion tests, sometimes company specific, were used to assess durability.
Additionally, from these tests it was not apparent that the exposure times equated to a 15-year service life.
This situation prompted the need to determine the corrosion resistance of the new steel systems using
standard test protocols that would indicate a 15-year service durability and was the genesis for the corrosion
study conducted by the Strategic Alliance for Steel Fuel Tanks (SASFT).
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HISTORICAL ASSESSSMENT
Historically, a three-stage process has been used to assess the corrosion performance of steel for fuel
tanks.
Bench Scale Simulative Corrosion Tests
These tests are conducted by steel suppliers and automakers alike. The tests are used primarily as
screening tests for further evaluation in full scale proving ground tests. Of the many tests that have
been used in the past, three of the most commonly used are a Neutral Salt Spray corrosion test (ASTM
B117) which exposes test strips or coupons to a continuous salt spray for a fixed time at a specified
temperature, a Cyclic corrosion test (SAE J2334) having prescribed cycles of exposure to salt spray and
dry times at specified temperatures for various times (cycles), and various Fuel Resistance tests where
company-preferred tests are used for any fuel of interest. Because of the concern regarding how well
simulative tests relate to actual on-vehicle performance, additional proving ground tests are always
conducted by all automakers.
Automotive Proving Ground Tests
Each automaker has its own prescription for assessing the corrosion resistance of fuel tanks.
Common features are formed tanks or shells and/or panels fixed to a sled or installed on a vehicle,
which is driven over a track while undergoing a 'menu' of exposures to salts, dry periods and
gravel.
Field Surveys of Actual Vehicles
Corrosion surveys of actual in-service vehicles (after 5 years, 10 years, 15 years, etc.) are conducted
regularly in areas of severe corrosion (such as the northeast of U.S.A., Florida or the maritime
provinces of Canada). These surveys evaluate the actual extent of corrosion of fuel systems, body
structures and body panels and validate proving ground tests and, to some extent, bench scale
simulation tests.
From the above assessments automakers are able to establish correlations. However, the predictability of
bench scale simulative tests is not sufficiently accurate to avoid conducting proving ground tests. Thus for
steel fuel tank materials, the durability performance assessment varies according to the assessment method as
follows:
Assessment Method
Performance Predictability
Bench scale simulative tests
Proving ground tests
Field surveys of corrosion
on vehicles
Indication only
Good measure of performance
Validation
Because SASFT did not have the capability to conduct proving ground tests and it was premature to
conduct field surveys because of the 'newness' of many steel systems, SASFT decided to conduct bench
scale simulative tests. It was envisioned that these tests, although only indicative of long-term service
durability, would provide encouragement for automakers to conduct their own proving ground tests for
the various new steel systems.
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SCOPE AND OBJECTIVES
Scope - It was regarded as important to adopt a broad scope with respect to the selection of steel systems
for corrosion testing - regardless of the regional origin of the steel systems. Because regionally-developed
steel systems can be migrated to other regions, several steel "options" can be considered by automakers for
15-year-life fuel tanks. The detailed analysis of costs, manufacturability and performance could be
determined subsequently by interaction between the individual steel companies, tank manufacturers and
automakers.
A somewhat narrower scope was adopted in selecting the corrosion tests:
The external tests were of recognized value primarily to North American automakers and suppliers.
But specific unique features were incorporated to reflect actual conditions experienced by an
automobile fuel tank rather than by body panels or body structures.
The internal fuel test selected was uniquely designed by SASFT, based on existing tests in Europe
and in Japan.
Objectives - The following objectives were established for SASFT's corrosion study:
Select suitable steel systems (available from worldwide steel industry) for meeting a 15-year life.
Select suitable bench-scale tests for assessing the durability performance of steels in an automotive
fuel tank environment; specifically external corrosion resistance (resistance to salts, stone
impingement, etc.) and internal corrosion resistance to aggressive fuels.
Obtain feedback from automakers on the value of the SASFT corrosion program before the tests were
started. In this way, the results would be meaningful to automakers.
Conduct the tests at an independent test laboratory (outside of the SASFT and AISI organizations).
Share the results with automakers and encourage their further evaluation of the steel systems using
proving ground or other tests.
To accomplish these objectives, a Corrosion Evaluation Team was formed which organized and managed
the program. The effectiveness of the team was enhanced by the ability of company representatives to draw
from the resource bases of their companies.
-8-
GENERAL CONSIDERATIONS
Testing Approach
Because of a lack of access to proving grounds and their infrastructure, SASFT decided to use established
accelerated bench scale corrosion tests. Several tests were considered by the Corrosion Evaluation Team;
two external tests and one internal test were selected.
Neutral Salt Spray Test (ASTM B117)
The CET was aware that there is a poor correlation of results from this test with actual perforation
corrosion of fuel tanks or body panels in proving ground tests or field surveys. However, because of
the wide use of the test and the large availability of data from other test programs, it was decided to
include the test. Furthermore, it was seen as valuable to determine whether any correlations could
be made with the results of the preferred external test, i.e. the Cyclic Corrosion Test (SAE J2334).
Cyclic Corrosion Test (SAE J2334)
Much work has been conducted on this test by the SAE J2334 Committee over the last 20 years.
This has culminated in recent papers indicating the value of the test as a practical means for
assessing perforation corrosion resistance [1 - 4]*. Information on the predictability of the J2334
Cyclic Corrosion test is reproduced from one of the referenced papers in APPENDIX 1. Currently,
the J2334 cyclic corrosion test is generally regarded as a useful simulative bench test for predicting
perforation performance in subsequent proving ground tests or in actual vehicle performance.
Therefore, SASFT selected the base J2334 test for evaluating the various steel systems. However,
modifications to the test procedure were incorporated to better represent the external conditions
experienced by fuel tanks. These include:
- a unique test specimen containing:
- a welded flange
- a plastic clip on the welded flange to provide potential crevice corrosion sites
- a scribe line simulating scratching down to bare steel
- a dome to simulate the formed areas of a fabricated steel tank
- a procedure for simulating gravel impact on a tank by using the standard SAE J400 Gravelometer
Test on a flat portion of the specimen.
Internal (Fuel) Corrosion Test
Features and elements of existing fuel corrosion resistance tests developed by Corus (Europe) and
JFE Steel (Japan) were incorporated into a SASFT designed, sealed cup test. The selection of
aggressive fuel CE10A was chosen on the basis of findings from a cooperative survey conducted by
the Big 3 automakers of the 'aggressiveness' of a variety of fuels. From this survey, CE10A was
found to be a very agressive fuel.
To ensure that the results from the SASFT corrosion test program would be valuable to automakers, the
original proposed tests, test specimens, test procedure and steel systems were reviewed with key engineering
personnel at automakers worldwide. As a result of feedback and suggestions, several modifications were
incorporated into the original SASFT test program.
Exposure Times and Life Equivalencies
For the Neutral Salt Spray Test, SASFT was unaware of any correlation between exposure time and equivalent
corrosion in a vehicle. Because North American auto manufacturers generally use exposure times of 1,000 to
2,000 hours, SASFT decided to use a 2,000-hour exposure time. For the Cyclic Corrosion Test, SASFT learned
from various corrosion experts that 80 cycles is generally regarded as being approximately equivalent to 10
years vehicle life on the basis of correlations between cyclic testing, automotive proving ground tests and field
* see references and notes at the end of this report.
-9-
surveys. Assuming a linear relationship between the number of cycles and life equivalency, 120 cycles should
represent 15 years. SASFT decided to run the Cyclic Corrosion Test beyond 120 cycles (15 years) and
complete the exposure after 160 cycles (20 years).
For the Fuel Corrosion Test exposures of 26 weeks to various fuels at 45°C are used by some automakers to
represent performance of an actual fuel tank after 10 years. Consequently, the exposure test period was
increased by 50% to simulate 15-year tank exposure.
The exposure times and life equivalency are summarized in EXHIBIT 1.
Exposure Times
Typically used by N.A.
Automakers
Neutral Salt Spray Test
(ASTM B117)
1000 to 2000 hours
Cyclic Corrosion Test
(SAE J2334)
80 cycles
SASFT
Exposure,
Time
2000 hours
160 cycles
26 weeks
Fuel Test
39 weeks
Approximate
Life Equivalency
(years)
——
——
10 years
20 years
10 years
15 years
EXHIBIT 1. Exposure times and life equivalency for various corrosion tests.
Steel System Candidates for Corrosion Testing
The global nature of SASFT's membership, particularly with respect to steel companies, enabled a broad
survey of candidate steel systems for corrosion testing to be conducted. Furthermore, the list of candidate
steel systems reflected the different preferred approaches to steel selection and tank manufacturing in
different geographical regions as shown in EXHIBIT 2.
Geographic region
North America
Big Three
Transplants
Europe
Japan/Korea
Preferred steel manufacturing approach for automobile fuel tanks
Pre-painted steel and limited post-painting
Post-painting of assembled tanks
Bare steels (HD Aluminized* and stainless) and
post-painting of HD Aluminized and stainless
Post-painting of assembled tanks
*Used largely by DaimlerChrysler (Mercedes) for tanks placed above the
floor pan and not exposed directly to road salts.
EXHIBIT 2. Preferred steel types and manufacturing methods for automobile fuel tanks by
geographical region.
An additional factor in selecting steel materials was a need to evaluate and compare the performance of
materials containing Cr+6 with those that are Cr+6 free. As a result of the above considerations, 12 steel systems
were chosen initially for the corrosion study. However, 2 post-paint systems were subsequently withdrawn
because of incorrect paint thicknesses. The remaining 10 systems and the suppliers of the test materials are
shown in EXHIBIT 3. (More complete details of the steel systems are described under test materials in the
subsequent section entitled “Experimental Procedures Adopted.”)
- 10 -
Category
Prepainted
steels
ID
No.
1
Other coating
Presence
of Cr +6
ISG
(Bethlehem)
Epoxy pre-paint water-based postpaint at welds
Yes
ISG
(Bethlehem)
No
U.S. Steel
(National)
No
4
Low carbon steel/
HD Aluminized Aℓ-Si**
ThyssenKrupp
Stahl
Yes
5
Austenitic
304L
stainless/
None
Low carbon steel/
HD Terne Pb-Sn
Arcelor
(J & L Specialty)*
Inorganic coating
No
Nippon Steel
Corp.
Acrylic and top coat
post-paint (external surface only)
No
7
Low carbon steel/
HD Tin Zinc (Sn-Zn)
Nippon Steel
Corp.
Acrylic and top coat
post-paint (external surface only)
No
8
Low carbon steel/
HD Aluminized Aℓ-Si
Arcelor
Alkyd resin synthetic polymer postpaint (external surface only)
Yes
9
Ferritic 436L stainless/
None
JFE Steel
Zinc-rich paint (external surface only)
No
10
Austenitic
stainless/
None
Arcelor
(J & L Specialty)*
None
No
3
Bare
steels
Supplier
of steel samples‡
Low carbon steel/
Electrogalvanized
Zn-Ni
Low carbon steel/
Electrogalvanized
Zn-Ni
Low carbon steel/
HD Galvannealed Zn-Fe
2
Postpainted
steels
Steel System
Base steel/Metallic
coating
6
304L
‡ The same steels may be available from other steel companies.
* Now part of Allegheny Ludlum.
** Subsequently referred to as HD Aluminized or HDAℓ
EXHIBIT 3. Steel systems selected by SASFT for external and fuel corrosion testing.
Criteria for Failure and Extent of Corrosion
Because the prime function of a fuel tank is to contain fuel, perforation of the test specimen was adopted as
the criterion for failure. Additionally, various qualitative and quantitative assessments of corrosion were
used to indicate the progress of corrosion up to the point at which perforation (failure) occurs. It was
expected that the progress of corrosion might differ from region-to-region on the specimen because of the
different conditions in the specimen such as forming deformation, scratches, weld zones, and gravel impact
zone. Therefore, in the External Tests corrosion assessments were made at several locations of the test
specimens which simulated different tank conditions (described later under Configuration and Preparation
of Specimens in the section Experimental Procedures Adopted).
For the Internal Corrosion Tests the extent of corrosion and pitting was assessed at several locations (liquid
contact, liquid-vapor interface, and vapor contact areas at the cup side walls and lids). In this way, the
specific 'corrosiveness' of the liquid fuel, liquid-vapor interface (including phase separation of the fuel) and
vapor could be determined.
Independent Testing
Although excellent corrosion testing facilities were available in many member companies of SASFT, it was
decided to contract the testing with a reputable testing laboratory whereby the testing and interpretation of
results is entirely independent of SASFT and its members. Accordingly, several testing laboratories with
experience in automotive corrosion testing were surveyed. After careful review, ACT Laboratories,
Hillsdale, Michigan, were contracted to conduct both the external corrosion testing and the fuel testing.
Key factors which merited the selection of ACT Laboratories were:
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Excellent capabilities in automotive corrosion testing.
Good reputation with the automotive community (OEMs and suppliers).
Extensive prior involvement with SAE J2334 committee in developing and validating the Cyclic
Corrosion Test.
Accessible laboratories in Hillsdale and Wixom, MI.
- 12 -
EXPERIMENTAL PROCEDURES ADOPTED
Test Methods
Details of the test procedures are described as follows:
The test was conducted according to ASTM B117 [5]. Key process parameters were:
- Continual atomized spray (or fog) of 5% salt solution in an enclosed chamber.
- Temperature of chamber: 35ºC.
- Triplicate specimens were spaced from each other and inclined at 15º from vertical.
- Maximum exposure time of 2000 hours.
- Gravel impact was conducted according to SAE J400 at the start of testing and after 500, 1000,
and 1500 hours of salt spray exposure.
The test was conducted according to SAE J2334 procedures [6]. Key process parameters were:
- One 24-hour cycle in an enclosed chamber included:
- 6 hours exposure in 100% condensing humidity at 50°C (+ 2°C).
- 15 minutes exposure at 25°C to a salt solution consisting of, 0.5% NaCl, 0.1% CaCl2
and 0.075% NaHCO3.
- 17.75 hours exposure in a dry stage (60°C + 2°C, 50% + 5% relative humidity).
A schematic of the daily cycle is shown in EXHIBIT 4.
- Duplicate specimens were spaced from each other and inclined at 15° from vertical.
- Gravel impact was conducted according to SAE J400 at the start of testing and after 20 cycle
intervals. Separate sets of specimens were used for 80-, 120-, and 160-cycle exposures.
- Six coupons of bare cold-rolled steel were included in the Cyclic Corrosion test for the purpose of
assessing weight loss and perforation for an uncoated steel (no metallic coating and no pre- or
post-paint.).
Humid Stage
6 hr.
50 C, 100% RH
Salt Dip
25 C, 15 min.
0.5% NaCl + 0.1%
CaCl2 + 0.075%
NaHCO3
Dry Stage
60 C, 50% RH
Daily
Dry Stage
17 hr., 45 min.
Weekends and
Holidays
60 C, 50% RH
EXHIBIT 4. Daily cycle for the Cyclic Corrosion Test (SAE J2334).
Test Validation Speciments
To ensure that the test conditions in both the Neutral Salt Spray and Cyclic corrosion tests were
stable within the duration of the tests and consistent with previous tests, test validation specimens
of pure zinc and uncoated steel sheet were incorporated in the test chambers. Weight loss of the
coupons was recorded as follows:
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Exposure, time/cycles
500 hrs.
1000 hrs.
80 cycles 120 cycles
1500 hrs.
160 cycles
2000 hrs.
——
Gravelometer Test
The test used in both the Neutral Salt Spray Test and the Cyclic Corrosion Test was conducted
according to SAE J400 (Revised 2002-11) [7]. Key process parameters were:
- A QGR gravelometer was used.
- Room temperature and an air pressure of 70 + 3 psi.
- 1 pint of water-worn road gravel that passes through a 16mm (5/8 inch) space screen,
but retained on a 9.5mm (3/8 inch) space screen.
- The gravel was aimed to impinge only on the target area immediately below the weld flange.
Fuel Test
The test fuel used was CE10A and constituted, in accordance with SAE J1681, [8] as follows:
- For 1 liter of Test Fuel (CE10A): 450 milliliters of Toluene
450 milliliters of iso-Octane
100 milliliters of Aggressive Ethanol
-
Aggressive Ethanol:
816.0 grams (1.034 liters) of Denatured Ethanol, CDA 20
8.103 grams (8.1 milliliters) of ASTM D 1193 - Type II Water
0.004 grams of Sodium Chloride
0.021 grams (11 microliters) of Sulfuric Acid
0.061 grams (58 microliters) of Glacial Acetic Acid
The test cups and lids (described later in Specimens for Internal Testing) were cleaned with warm
water, dried and weighed before adding 30 ml of the test fuel, which half-filled each cup. The
assembled fuel test cups were placed in a sand bath controlled to 45 ± 2°C according to the test
procedures of SAE J1747 [9]. Total exposure time for the stationary fuel test assemblies was 39
weeks to simulate a 15-year fuel tank exposure. To simulate regular and re-filling of a fuel tank and
to replenish contaminant ions and minimize oxygen depletion (per SAE J1747). Each fuel test
assembly was removed from the sand every four weeks, the fuel was removed and saved, the cup
and lid reweighed, new fuel added and the assembly returned to the sand bath. The spent fuel was
checked for any discoloration.
Configuration and Preparation of Test Specimens
Specimens for External testing (Neutral Salt Spray and Cyclic tests)
Historically, for bench scale corrosion testing of steel, the test specimens have been flat coupons with
some form of edge protection (tape or stop-off paint). In some cases the specimens might contain a
scribe line and a dome to simulate a scratch and forming strains, respectively. The Corrosion
Evaluation Team of SASFT felt that the test specimen for this study ought to represent more fully the
conditions experienced by steel in an assembled fuel tank. Accordingly, the unique test specimen
shown in EXHIBIT 5 was developed for both of the external corrosion tests.
- 14 -
Olsen
dome
6 inches
Weld
6 inches
Plastic
Clip
scribe line (applied
at test laboratory)
4 inches
gravel
impact
zone
2 inches max. flange width
EXHIBIT 5. Specimen configuration for both External Corrosion tests
- 15 -
The 4-inch wide test specimen included:
- an Olsen dome to simulate forming strains. The 22.22mm (7/8th inch) diameter dome is formed
to a depth of 7.9mm (0.3 inch). The domes were introduced into the steel specimens according
to ASTM E643-84 (Re-approved 2000). [10]
- a scribe line such that the bare steel is exposed to simulate a severe scratch. The scribing was
conducted according to ASTM D1654 - 00 [11] using a straight shank lathe tool (style E).
- a welded flange area to simulate the electric resistance seam weld of a steel fuel tank.
- a plastic clip to provide potential crevice-corrosion sites.
- a gravel impact zone for simulation of frequent over-the-road stone chipping.
All test specimens were protected at the cut edges by a stop-off paint (Microstop). A photograph of a
test specimen is shown in the inset in EXHIBIT 5.
Specimens for Internal Testing (Fuel tests)
A unique sealed fuel test cup was developed and used for the fuel resistance tests. 50 mm diameter
cups were drawn to a depth of 30 mm with a residual cup flange. The cup was half filled with 30 ml of
the test fuel so that the cup was exposed to the fuel and vapor while the lid was exposed only to the
vapor. To seal the fuel and vapor, a 1/8 inch thick Viton® flange gasket [12] was placed on top of the
flange surface of the cup, the lid positioned and clamped by upper and lower ¼ inch thick steel
clamping rings secured with 4 equally spaced bolts [13]. A torque wrench was used to apply a fixed
torque of 1.1 Newton-meter (10 inch-pounds) to each of the 4 bolts. The fuel test components
(including the torque wrench) are shown in EXHIBIT 6. A schematic representation of the fuel test
assembly and a photograph of the assembly are shown in EXHIBITS 7 and 8, respectively.
EXHIBIT 6. Components of the fuel test unit: torque wrench, fuel-containing cup, Viton® gasket seal,
steel sample lid, bottom clamping ring, top clamping ring and the combined lid plus top clamping ring.
- 16 -
Viton
Gasket
seal
4 Clamping
bolts
Steel sample for lid
Circular steel
clamping rings
30mm
Drawn sample cup
Fuel
50mm
Blank diameter
Punch diameter
Die radius
Clamping torque
Draw depth
=
=
=
=
=
98 mm
50 mm
3 mm
1.1 newton-meter (10 inch pounds)
30 mm
EXHIBIT 7. Schematic of the fuel test assembly fully immersed in a temperature-controlled sand bath.
To maintain a constant temperature of 45± 2°C, the fuel test assemblies were placed in a controlled
temperature 10 inch (254 mm) deep sand bath. The test assemblies remained stationary for each 4-week
exposure.
EXHIBIT 8. Profile of an assembled test cup unit.
- 17 -
Fabrication of Test Specimens
Flat steel-system sheets were supplied by various steel companies to a target thickness of 1mm (0.0395
inch). For External Corrosion test specimens, the various sheets were welded, either by using a
conventional seam welding technique, or by a Soudronic process using production welding
practices. The welded specimens of pre-painted steels were post-painted at the weld zone. All
welded specimens were gathered at Bethlehem Steel Corporation (now International Steel Group)
where the Olsen domes were formed. All specimens were then shipped to ACT Laboratories where
any forming lubricants were removed by light washing and the scribing and edge painting was
completed before testing. For Internal Corrosion test specimens, all the fuel cups were deep drawn
and the flat lids cut at Bethlehem Steel using the same uniform procedures for each material. The
specimens were then shipped to ACT Laboratories for cleaning, drying and assembly with gaskets.
Evaluation Procedures
External - Neutral Salt Spray Test
The qualitative evaluation of Neutral Salt Spray specimens was conducted at every 500 hours before
and after air drying and cleaning by blowing air at 80 psi at an angle of approximately 45º over the
entire specimen surface. The specimen surface was lightly contacted with the air nozzle to clean
the surface by removing loosely adherent coatings.
Each of the triplicate specimens was visually examined for corrosion and loss of adhesion at the
scribe line, chipped (graveled) area, Olsen dome, flange (including weld and clip locations) and
field area (region above the dome). The extent of corrosion was rated according to the following
scale and assigned a numerical rating as follows:
Corrosion Severity
Numerical Rating
N = None: No corrosion
0
S = Slight: Approximately less than 15% corrosion in test area
1
M = Moderate: Approximately 15 - 30% corrosion in test area
2
P = Pronounced: Approximately greater than 30% corrosion in test area
3
The quantitative evaluation of the Neutral Salt Spray specimens was conducted at the completion of
testing (i.e., after 2000 hours) by four methods:
- Weight loss.
- Creepback from scribe line. The distance of the affected paint film (lost or non-adherent) between
the scribe line and the unaffected paint film was reported as:
- Average: The average of 6 measurements of creepback from the scribe at points 10mm apart
centered on the scribe line. Each measurement was an average of the creepback on two
sides of the scribed line.
- Maximum: A measurement of the creepback from the scribe line at the point having the
most extensive amount of affected paint, but discounting those areas less than 1cm from the
ends of the scribe line.
- Minimum: A measurement of the creepback from the scribe at the point with the least
extensive amount of affected paint, but discounting those areas less than 1cm from the ends
of the scribe line.
- Pit depth. Maximum pit depth (greater than 0.1mm, which is approximately 10% of the initial
specimen thickness) was measured for each specimen after 2000 hours.
- Chip rating. The test method and evaluation procedure is described below under the
Gravelometer Test method.
- 18 -
A summary of the qualitative and quantitative assessments for the Neutral Salt Spray test is shown in
EXHIBIT 9.
500
Qualitative
Photographs
Before cleaning
After cleaning
Visual assessment
After cleaning
Quantitative
Creepback
Pit Depth
Chip rating
Exposure time, hours
1000
1500
2000
√
√
√
√
√
√
√
√
√
√
√
√
——
——
√
——
——
√
——
——
√
√
√
√
EXHIBIT 9. Qualitative and quantitative assessment of corrosion in the
Neutral Salt Spray test.
External - Cyclic Corrosion Test
A qualitative evaluation was conducted after every 20 cycles by visually assessing, after air blowing
but without cleaning, the extent of corrosion and loss of any coating adhesion at the scribe line,
chipped (graveled) area, Olsen dome, flange (including weld and clip locations) and field area (region
above the dome). The extent of corrosion or adhesion loss was rated the same way for the Neutral
Salt Spray specimens. The specimens were also photographed.
The quantitative evaluation was conducted after 80 cycles, 120 cycles and 160 cycles of exposure. The
specimens were air dried and cleaned using 80 psi air pressure at a 45° angle over the entire specimen
surface. The specimen surface was lightly contacted by the air nozzle to remove loosely adherent
coatings. Weight loss, creepback, pit depth, and chip ratings were assessed in the same way as for the
Neutral Salt Spray test. A summary of the qualitative and quantitative assessments for the Cyclic
Corrosion test is shown in EXHIBIT 10.
60
Qualitative Evaluation
Remove specimens temporarily and
without cleaning:
― assess corrosion damage
according to ASTM D610
― take photographs
Quantitative Evaluation
Remove specimens permanently,* clean
and then:
― weigh
― assess creep back
― determine pitting location and
depth
No. of Cycles (life equivalency)
80
100
120
140
(10 years)
(15 years)
160
(20 years)
√
√
√
√
√
√
√
√
√
√
√
√
——
——
——
√
√
√
——
——
——
√
√
√
——
——
——
√
√
√
* Separate sets of specimens were used for 80-, 120-, and 160-cycle exposures.
EXHIBIT 10. Qualitative and quantitative assessment of corrosion in the Cyclic Corrosion test.
- 19 -
Gravelometer Test
The evaluation procedure used was based on visual comparison of the test specimens with SAE J400
pictorial standards. A number-letter combination in which rating numbers 10-0 indicate the
number of chips of each size and rating letter A-D designate the sizes of the corresponding chips.
The codes are described fully with the tabulated results in subsequent EXHIBITS and APPENDIXES.
Additionally, the nature of failure was noted as to whether adhesion loss occured from the metallic
coating to topcoat or from the steel substrate to topcoat.
Internal Fuel Test
The qualitative evaluation was conducted by inspecting the fuel test cups and lids after each fuel
change and assessing of the extent of corrosion. The same visual rating scale was used as for the
external tests. The quantitative evaluation was conducted by measuring the weight loss (change) and
the extent, location and depth of pits.
Test Materials (steel systems)
The steel systems used for External Corrosion testing are shown in EXHIBIT 11, together with a description
of the external surfaces exposed to the corrosion environments.
Coatings on both sheet surfaces
I.D.
Number
Base
Steel
Metallic
Coating/Coating
weight per side
Exterior Surface
Post-paint
thickness
Sheet
Thickness
mm*
Pre-treatment
/thickness
Pre-paint/
thickness
Magni 331
+6
with Cr
epoxy
/9.5 µm
Magni 336
+6
non- Cr
epoxy
/9.5 µm
Weld only Magni W46 /
127µm (both sides of flange)
Magni 336
+6
non- Cr
epoxy
/9.5 µm
Magni 369
+6
with Cr
epoxy /9µm
Neukote
inorganic
coating /
17µm
None
Anti chip acrylic /350µm +
Pre-painted steels
1
Low carbon (IF)
steel
Electrolytic Zn-Ni
/30 g/m2
1.07
2
Low carbon (IF)
steel
Electrolytic Zn-Ni
/30 g/m2
1.07
3
Low carbon (IF)
steel
Hot dip
galvannealed
(Zn-Fe) /45 g/m2
0.8
4
Low carbon (IF)
steel
0.88
5
Austenitic
Stainless (304L)
Hot dip
aluminized (Al-Si)
/30 g/m2
None
0.89
Bonderite 1303 mixed
oxide with Parcolene
62 Cr+6 rinse / 92
10mg/m
+6
350 non- Cr rinse /910mg
2
/m
+6
350 non- Cr rinse /92
10mg/m
Bonderite 714 with
+6
Parcolene 62 Cr
rinse
None
Hot dip terne (PbSn) /40 g/m2
Hot dip tin-zinc
(Sn-Zn) /40 g/m2
Hot dip
aluminized (Al-Si)
/55 g/m2
None
0.8
Phosphate /3 mg/m2
0.8
Cr & Cr free resin
/300 mg/m2
Chromate
(i.e., with Cr+6)
None
None
Anti chip alkyd resin
(Helmebath) /150µm
0.8
None
None
Zinc rich paint/20µm
None
0.8
None
None
Bare
None
(Neukote pre-paint only)
Post-painted steels
6
7
8
9
Low carbon
(DQSK)
Low carbon
(DQSK)
Low carbon
(DQSK )
Ferritic
stainless (436L)
Bare steels
10
Austenitic
Stainless (304L)
Coverpaint / 20µm
0.9
+3
+6
Anti chip acrylic /350µm +
Coverpaint / 20µm
*Thickness before pre- or post-painting
EXHIBIT 11. Description of the pre-painted, post-painted and bare steels for EXTERNAL CORROSION
resistance testing.
- 20 -
In addition to the 10 materials shown in EXHIBIT 11, two other post-painted steel systems were selected for
external corrosion testing, but were withdrawn after early testing because of incorrect post-paint thicknesses.
Photographs of the initial test specimens for each test material are shown in EXHIBIT 12; the specimens
received an initial gravel impact, but no exposure either to Neutral Salt Spray or to the Cyclic test. The
different colors and textures reflect the different coatings and approaches to resisting external corrosion.
EXHIBIT 12. Photographs of initial test specimens (materials #1-#10) for external corrosion testing.
All of the steel systems used in the SASFT study represented products in commercial production by the
supplying steel companies. Further information on specific steel systems can be obtained from the supplying
steel companies shown in EXHIBIT 4.
- 21 -
RESULTS AND DISCUSSION
External - Neutral Salt Spray Test (ASTM B117)
Qualitative Evaluation after 2000 hours of exposure
Photographs of all test materials after 2000 hours of exposure are shown in EXHIBIT 13. Additional
photographs of initial samples (graveled, but zero exposure time), and after 1000 hours, and 2000
hours exposure are shown in Photo Library - Neutral Salt Spray. The identification of the photos and
test specimens are shown in the Photo Library - LISTING 1 at the end of this report.
Pre-painted steels
#1
#2
#3
#4
#5
Post-painted steels
Bare steels
#6
#7
#8
#9
#10
EXHIBIT 13. Photographs of test materials after 2,000 hours exposure and before cleaning in Neutral Salt
Spray.
Detailed visual ratings of the severity of white and red rust at eight different locations of triplicate
specimens are shown in APPENDIX 2. The overall numerical ratings are displayed in EXHIBIT 14.
- 22 -
EXHIBIT 14. Average corrosion severity display of the visual ratings of white and red rust after 2000
hours of exposure in the Neutral Salt Spray test. White 'rust' for pre-, and post-painted samples may
well be a reaction product with the specific paints. (Numeric Corrosion Severity ratings: 0=None,
1=Slight, 2=Moderate, and 3=Pronounced visible corrosion as described in APPENDIX 2.)
EXHIBIT 14 shows that moderate white rusting at several locations for pre-painted HDGA (#3) and at the
dome for pre-painted HDAl (#4) . For those pre- and post-painted steels which showed slight to moderate
white rusting, the white 'rust' could have been the result of reaction with the paint films. For red
rusting, moderate to pronounced severities were shown by only the post-painted HDAl (#8) test material.
- 23 -
Quantitative Evaluation After 2000 Hours of Exposure
The weight loss data for the test materials and the test validation coupons are shown in APPENDIXES
3 and 4 respectively. The percentage weight losses are shown graphically in EXHIBIT 15. The
percentage weight losses of all specimens were very low (2% maximum) compared with the
bare cold rolled steel test validation sample (12.9% loss), which indicates the effectiveness of the
corrosion resistant mechanisms utilized by the various steel systems. The 2% weight loss of the
post-painted HD Aluminized sample (#8) undoubtedly resulted from the loss of adhesion and
blistering of the thin paint film (150µm) in all areas of the specimen (see Note 4 in APPENDIX 2).
This is confirmed by the extensive creepback observed for the HD Aluminized (#8) material (see
APPENDIX 5). The only severe creepback occurred in the post-painted HD Aluminized steel (#8)
and was probably related to the adhesion loss of the post-paint. APPENDIX 5 also shows that no
pits deeper than 0.1mm were observed in any location in any specimen.
Weight loss, % (validation coupons)
60
Zinc
1500 hrs.
50
Bare
CR steel
40
Weight change % (test materials)
4
30
POST-PAINTED STEELS
PRE-PAINTED STEELS
2
1.1
10
Loss
0.2
0.05
-0.2
0.2
0.05
#1
#2
#3
#4
#5
#6
#7
#8
#9
304L
436L
HDAl
Sn-Zn
HDAl
0
Gain
HDGA
Bare Stee l
0.7
0.3
Zn-Ni
Zn
Zn-Ni
0
2
0.6
Terne
1500
hrs.
2000
hrs.
304L
20
BARE
STEELS
#10
-2
EXHIBIT 15. Percentage weight losses (gains) of test validation samples (left) and steel test specimens
(right) in the Neutral Salt Spray Test after 2000 hours exposure.
The detailed gravelometer chip rating number (denoting the number of chips) and the rating letter
(denoting size of the chips) and loss of adhesion for the steel system specimens after 500, 1000, 1500,
and 2000 hours exposure are shown in APPENDIX 6. The results for 2000 hours exposure are
summarized in EXHIBIT 16.
- 24 -
Chip frequency rating
Size rating &
size range of chips
Rating numbers
0
1
2
3
4
5
6
7
8
9
10
A
B
C
D
Number of chips
>250
150250
100159
7599
5074
2549
1024
5-9
2-4
1
0
<1mm
1-3
mm
3-6
mm
>6
mm
Pre-painted steels
#1 EG Zn-Ni+Cr6
#2 EG Zn-Ni- Cr6
#3 HDGA- Cr6
#4 HDAℓ+ Cr6
#5 304L+Neukote
Post-painted steels
#6 HD Terne
#7 HD Tin-Zinc
#8 HDAℓ
#9 Ferritic436L
Bare steel
#10 Austenitic 304L
1
X
X
X
X
X
1
X
1
X
1
X
X
No rating due to excessive blistering
X2
X
X
X
X
1 denotes loss of adhesion from metallic coating to topcoat
2 denotes loss of adhesion from steel to topcoat.
EXHIBIT 16. Summary of gravelometer chip ratings after 2000 hours exposure in the
The best chipping resistance was shown by those post-painted steels that had very heavy coatings (#6 & #7)
and by the Austenitic 304L steel with inorganic pre-paint (#5).
External - Cyclic Corrosion Test (SAE J2334)
Qualitative Evaluations
Photographs of all test materials after 160 cycles exposure prior to cleaning are shown in EXHIBIT
17. Additional photographs of cyclic corrosion test specimens are shown in Photo Library-Cyclic
Test, identification codes for which are shown in Photo Library - LISTING 2 at the end of this
report.
Visual ratings of the severity of white and red rust at eight different locations for duplicate
specimens are shown in APPENDIXES 7, 8 and 9 after exposure times of 80, 120 and 160 cycles,
respectively. (Rust staining was not included in the ratings.)
The numerical corrosion severity ratings of 0, 1, 2, and 3, are charted in EXHIBITS 18 and 19 for 120
cycle and 160 cycle exposures. The displays show moderate to pronounced white rusting only at the
dome location of pre-painted HDGA (#3) and the flange area of post-painted HDAl (#8). For red
rusting, moderate to pronounced severities occurred after 120 and 160 cycles at the weld clip for
pre-painted Zn-Ni (#1), the scribe for pre-painted HDGA (#3), and the weld and flange for the postpainted HDAl.
- 25 -
Pre-painted steels
#1
#2
#3
#5
Post-painted steels
#4
#6
#7
#8
#9
Bare steel
#10
EXHIBIT 17. Photographs of test materials after 160 cycles exposure and before cleaning in the Cyclic
Corrosion test. (No photograph for before cleaning was available for #3. Hence, the photograph for after
cleaning is shown.)
- 26 -
EXHIBIT 18. Average corrosion severity display from the visual ratings of white and red rust after 120
cycles of exposure in the Cyclic Corrosion test. (Numeric corrosion severity ratings: 0=None, 1=Slight,
2=Moderate, and 3=Pronounced visible corrosion shown in APPENDIX 8.)
- 27 -
EXHIBIT 19. Average corrosion severity display from the visual ratings of white and red rust after 160
cycles of exposure in the Cyclic Corrosion test. (Numeric corrosion severity ratings: 0=None, 1=Slight, 2=
Moderate, and 3= Pronounced visible corrosion shown in APPENDIX 9.)
- 28 -
Quantitative Evaluations
The detailed weight changes after 80 cycles, 120 cycles and 160 cycles exposure in the Cyclic
Corrosion test are shown in APPENDIXES 10, 11 and 12, respectively. To facilitate a comparison of
the different steel test materials, the weight change data after 160 cycles exposure has been plotted
in EXHIBIT 20. The greatest loss (2.42%) was shown by the post-painted ferritic 436L (#9) and can
be attributed to the loss of the thin paint coating because no evidence of substrate corrosion was
observed.
Weight loss, % (average for bare cold rolled steel controls), after 80 cycles
100
80
Bare cold rolled
steel control
(80 Cycles)
76.0
Weight change, % (test materials) – after 160 cycles
60
4
40
Pre-painted steels
Post-painted steels 2.42
Bare
steel
2
20
0.55
#3
#4
#5
#6
#8
#9
#7
304L
-0.57
436L
#2
-0.33
-0.12
HDAl
#1
Zn-Ni
Gain
-0.15
Sn-Zn
-0.12
Terne
-0.3
304L
0.09
0
Zn-Ni
Bare Steel
HDAl
0
0
HDGA
Loss
#10
-2
EXHIBIT 20. Average weight loss of cold rolled controls after 80 cycles and weight changes of steel test
materials after 160 cycles exposure in the Cyclic Corrosion Test.
In those instances where weight losses occurred, the percentage weight loss was very small (2.42%
maximum) especially when these data are compared with the high weight loss (76%) shown by the
bare cold rolled steel control after only 80 cycles, at which point the remnants of the samples were
removed from the Cyclic Corrosion test cabinet. The substantial weight loss of the bare cold rolled
controls confirms the severity of the Cyclic Corrosion test and the good resistance of the test materials
chosen for this study. (The detailed weight loss data for the cold rolled steel control specimens are
shown in APPENDIX 13.)
Average creepback and average maximum pit depths for 80 cycles, 120 cycles and 160 cycles
exposure to the Cyclic Corrosion test are summarized in EXHIBIT 21. (The detailed measurements are
shown in APPENDIXES 14, 15 and 16.) Moderate to pronounced creepback occurred in only two postpainted test materials (HDAl #8 and Ferritic 436L #9) due to adhesion loss of the post-paint film. After
80 and 120 cycles of exposure, maximum pit depths of 0.1 and 0.2mm were observed for the two prepainted EG Zn-Ni materials (#1 & #2) and 0.4 mm for pre-painted HDAl (#4).
- 29 -
Number of Cyclic Corrosion test cycles
80
120
160
80
120
160
Pre-painted steels
#1 EG Zn-Ni + Cr6
#2 EG Zn-Ni - Cr6
#3 HDGA - Cr6
#4 HDAℓ + Cr6
#5 304L + Neukote
Post-painted steels
#6 HD Terne
#7 HD Tin-Zinc
#8 HDAℓ
#9 436L
Bare steel
#10 304L
Creepback from scribe
mm
Maximum
pit depth /mm
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.2*
0.1*
0
0
0
0.4* 0.4*
0
0
0
0
0
0
0
0
0
0.6
6.9
0
0
0.1
NR
0
0
0.5
2.5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NR = no rating due to pronounced adhesion loss
* = max. pit depth occurred in the gravel area
EXHIBIT 21. Average creepback and average maximum pit depths after 80, 120 and 160 cycles exposure
in the Cyclic Corrosion test.
The pitting results for all materials are shown graphically in EXHIBIT 22 (A-C). All of the pits were
observed at the gravel area and the variance associated with gravel impact probably accounts for
the fact that no pits were observed after 160 cycles. It is important to understand that separate sets
of specimens were used for the 80, 120 and 160 cycle specimens, it is not necessary to expect their
occurence in the 160-cycle set of specimens. The origination of the pits was likely more dependent
on the nature of the gravel impact than on exposure in the Cyclic Corrosion Test.
EXHIBIT 22(A). Pit depths for the 80-cycle exposure set of specimens in the Cyclic Corrosion Test.
- 30 -
EXHIBIT 22(B). Pit depths for the 120-cycle exposure
set of specimens in the Cyclic Corrosion Test.
EXHIBIT 22(C). Pit depths for the 160-cycle exposure
set of specimens in the Cyclic Corrosion Test.
The detailed gravelometer chip ratings are shown in APPENDIXES 17, 18 and 19. A summary of data
after 160 cycles is shown in EXHIBIT 23. The pre-painted steels, in general, had 10 - 74 chips that were
less than 1 mm in size. For the post-painted steels, a higher frequency (50 - 159) of chips of larger size
(3 - 6 mm) were observed for the HDAl (#8) and Ferritic the 436L (#9) steels, which resulted from the
paint adhesion loss. By comparing the 160 exposure data Ferritic (EXHIBIT 23) with data from 20 cycle
exposure (see EXHIBIT 24), it can be seen that there is little change in chip rating and size for the prepainted steels. This indicates that the gravel impact determines the chip ratings more than the
corrosion exposure cycles. However, for the post-painted materials (#8 & #9), the chip frequency
increased somewhat as the corrosion exposure (and number of gravel impacts) increased.
Chip frequency rating
Size rating &
size range of chips
Rating numbers
0
1
2
3
4
5
6
7
8
9
10
A
B
C
D
Number of chips
>250
150250
100159
7599
5074
2549
1024
5-9
2-4
1
0
<1
mm
1-3
mm
3-6
mm
>6
mm
X
X
X
X
X
X
X
X
—
—
—
—
—
—
X
X
—
—
X
—
—
—
—
Pre-painted steels
6
#1 EGZn-Ni+Cr
#2 EGZn-Ni-Cr6
6
#3 HDGA-Cr
6
#4 HDAℓ+Cr
#5 304L+Neukote
#6 HD Terne
#7 HD Tin-Zinc
#8 HDAℓ
#9 436L
1
X1
X1
X
2
X
Post-painted steels
1
X
X2
1
X2
X
Bare Steel
#10 304L
1 denotes adhesion loss between metallic coating and topcoat
2 denotes adhesion loss between steel and topcoat
EXHIBIT 23. Summary of gravelometer chip ratings after 160 cycle exposure in Cyclic Corrosion Testing.
- 31 -
Chip frequency
Size rating &
size range of chips
Rating numbers
0
1
2
3
4
5
6
7
8
9
10
A
B
C
D
Number of chips
>250
150250
100159
7599
5074
2549
1024
5-9
2-4
1
0
<1
mm
1-3
mm
3-6
mm
>6
mm
—
—
—
—
—
—
—
—
—
—
—
6
Pre-painted steels
#1 EGZn-Ni+Cr
6
#2 EGZn-Ni-Cr
6
#3 HDGA-Cr
1
X
1
X
X
X
X
1
X
6
1
#4 HADℓ+Cr
#5 304L+Neukote
X
X
—
X
Post-painted steels
#6 HD Terne
#7 HD Tin-Zinc
#8 HADℓ
#9 436L
X
X
1
X
—
—
X
2
X
X
Bare Steel
#10 304L
X
—
—
1 denotes adhesion loss between metallic coating and topcoat
2 denotes adhesion loss between steel and topcoat
EXHIBIT 24. Summary of gravelometer chip ratings after 20 cycles of exposure in the Cyclic Corrosion
Testing (from the set of specimens used for the 160-cycle evaluations shown in EXHIBIT 23).
Internal Fuel Test
The steel systems tested in the fuel test are re-listed in EXHIBIT 25 to show the type of surface exposed to the
fuels. (A more detailed description of the steels and surfaces has already been given in EXHIBIT 11).
Steel
ID
Number
Bare Steel
Metallic
Coating
Surface Exposed
to the Test Fuel
Pre-painted category of steels
1
Low carbon steel
EG Zn-Ni
Metallic coating + Magni pre-paint (with Cr+6)
2
Low carbon steel
EG Zn-Ni
Metallic coating + Magni pre-paint
+6
(without Cr )
3
Low carbon steel
Hot dip galvannealed
Metallic coating + Magni pre-paint
+6
(without Cr )
4
Low carbon steel
Hot dip aluminized
Metallic coating + Magni pre-paint (with Cr )
5
Austenitic stainless
None
Steel + Neukote inorganic coating
+6
Post-painted category of steels
2
6
Low carbon steel
Hot dip terne
Metallic coating + Phosphate (3mg/m )
7
Low carbon steel
Hot dip Tin-Zinc
Metallic coating + Cr-free resin (300mg/ m )
8
Low carbon steel
Hot dip Aluminized
Metallic coating + Chromate
9
Ferritic stainless steel
None
Bare steel
None
Bare steel
2
Bare steels category
10
Austenitic stainless
EXHIBIT 25. Summary of steels used for fuel resistance testing showing the nature of the surface exposed
to the test fuel. (For details of the metallic coatings and exterior surface paints, see EXHIBIT 11.)
- 32 -
Qualitative Evaluations
The photographs of initial fuel test specimens after 28 weeks and 39 weeks exposure are shown in
the attached file Photo Library for Fuel Test, for which identity codes are shown in Photo Library –
LISTING 3. The detailed visual observations are shown in APPENDIXES 20 to 29. Except for one
pin-point red rust spot on the lid of one specimen (pre-painted EG Zn-Ni #1) after 20 weeks, the
only surface change observed was the appearance of a white residue. It was unclear whether the
white residue represented corrosion of the steel or a reaction product with the fuel. The extent of
the white residue was recorded according to the same rating scale used in visually rating the
external corrosion test specimens. The numerical visual ratings are shown in EXHIBITS 26, 27
and 28.
EXHIBIT 26. Extent of white residue at the fuel-contact area of the test cups. (Numeric ratings:
0=None, 1=Slight, 2=Moderate, and 3=Pronounced visible residue shown in APPENDIXES 20-29.)
For the fuel-contact area, only one material (Terne, #6) showed moderate to
pronounced white residue after 39 weeks.
- 33 -
EXHIBIT 27. Extent of white residue at the fuel-vapor interface area of the test cups. (Numeric ratings:
0=None, 1=Slight, 2=Moderate, and 3=Pronounced visible corrosion shown in APPENDIXES 20-29.)
In general, the extent of white residue was more severe at the fuel-vapor interface area, EXHIBIT
27. At this location, although there was zero residue for the four pre-painted materials (#1-#4)
after all exposures, moderate to pronounced residue was observed for all other materials starting at
28 weeks of exposure. This might be expected in view of the minimal coating or absence of coatings
in the latter materials.
EXHIBIT 28. Extent of white residue at the vapor area of the test cups. (Numeric ratings: 0=None,
1=Slight, 2=Moderate, and 3=Pronounced visible residue shown in APPENDIXES 20-29.)
- 34 -
At the vapor-contact area, only moderate residues were observed for one material (Terne, #6)
after 32 weeks of exposure. It should be emphasized that, although the moderate and
pronounced ratings refer to the area affected, the depth or thickness of the white residue was so
small that no scrapings could be taken to conduct an analysis of the residue.

Quantitative Evaluation for Fuel Test
The weight changes for the fuel test cups and lids are summarized in EXHIBITS 29 and 30
respectively, after the full 39 weeks exposure. (The detailed actual weights and progressive
weight losses from 0 to 39 weeks for cups and lids are shown in APPENDIXES 30 to 33).
CUPS:
Initial
(g)
Final (g)
Change
(g)
% Weight loss (Gain)
Actual
Rounded
Pre-painted steels
1. EG Zn-Ni
6
+Cr
2. EG Zn-Ni 6
Cr
6
3. HDGA - Cr
6
4. HDAℓ + Cr
5. 304L
Stainless
+ Neukote
58.7196
59.5354
59.1027
61.1080
61.2032
60.2463
50.1409
50.8337
50.6874
56.1806
56.2672
56.1086
69.8092
69.7561
69.4543
58.7143
59.5312
59.0974
61.1033
61.1976
60.2422
50.0802
50.7798
50.6291
56.1725
56.2588
56.0961
69.8172
69.7608
69.4563
-0.0053
-0.0042
-0.0053
-0.0047
-0.0056
-0.0041
-0.0607
-0.0539
-0.0583
-0.0081
-0.0084
-0.0125
0.0080
0.0047
0.0020
-0.0090
-0.0071
-0.0090
-0.0077
-0.0068
-0.0068
-0.1211
-0.1060
-0.1150
-0.0144
-0.0149
-0.0223
0.0115
0.0067
0.0029
0.01
0.01
0.01
0.01
0.01
0.01
0.12
0.11
0.12
0.01
0.01
0.02
0.01
0.01
0
51.1515
51.1739
51.1658
51.3344
51.3981
51.3340
54.6739
54.7048
54.5910
50.8958
50.8646
50.7450
51.1299
51.1572
51.1552
51.3294
51.3946
51.3303
54.6732
54.7047
54.5829
50.8956
50.8663
50.7481
-0.0216
-0.0167
-0.0106
-0.0050
-0.0035
-0.0037
-0.0007
-0.0001
-0.0081
-0.0002
0.0017
0.0031
-0.0422
-0.0326
-0.0207
-0.0097
-0.0068
-0.0072
-0.0013
-0.0002
-0.0148
-0.0004
0.0033
0.0061
0.04
0.03
0.02
0.01
0.01
0.01
0
0
0.01
0
0
(0.01)
69.0016
69.0689
69.1909
69.0003
69.0702
69.1894
-0.0013
0.0013
-0.0015
-0.0019
0.0019
-0.0022
0
0
0
Post-painted steels
6. HD Terne
7. HD Tin-Zinc
8. HDAℓ
9. Ferritic
Stainless
Bare Steel
10. 304L
Stainless
* No painted surface in contact with fuel.
EXHIBIT 29. Weight changes for the fuel test cups after the maximum exposure to the fuel of 39 weeks.
- 35 -
LIDS:
Initial
(g)
Final (g)
Change
(g)
% Weight Loss
Actual
Rounded
Pre-painted
1. EG Zn-Ni
6
+Cr
2. EG Zn-Ni 6
Cr
6
3. HDGA - Cr
6
4. HDA? + Cr
5. 304L
Stainless
+ Neukote
33.5038
33.5193
33.4456
34.4235
34.3345
34.1355
28.531
29.1547
29.2427
31.793
31.7794
31.7456
39.4244
39.4167
39.3869
33.4993
33.5149
33.4413
34.4089
34.3234
34.1257
28.4939
29.1163
29.2038
31.7728
31.7592
31.7225
39.4241
39.4166
39.3869
-0.0045
-0.0044
-0.0043
-0.0146
-0.0111
-0.0098
-0.0371
-0.0384
-0.0389
-0.0202
-0.0202
-0.0231
-0.0003
-0.0001
0.0000
-0.0134
-0.0131
-0.0129
-0.0424
-0.0323
-0.0287
-0.1300
-0.1317
-0.1330
-0.0635
-0.0636
-0.0728
-0.0008
-0.0003
0.0000
0.01
0.01
0.01
0.04
0.03
0.03
0.13
0.13
0.13
0.06
0.06
0.07
0
0
0
28.9321
29.0172
28.9316
30.8197
30.7312
30.7848
28.5956
28.6851
28.6737
28.7993
28.7165
28.8122
28.9327
29.0174
28.9318
30.8178
30.7313
30.7848
28.5961
28.6863
28.6740
28.7958
28.7125
28.8081
+0.0006
+0.0002
+0.0002
-0.0019
+0.0001
0
+0.0005
+0.0012
+0.0003
-0.0035
-0.0040
-0.0041
+0.0021
+0.0007
+0.0007
-0.0006
+0.0003
0
+0.0017
+0.0042
+0.0010
-0.0122
-0.0139
-0.0142
0
0
0
+0.01
39.079
38.9524
39.0745
39.0784
38.952
39.0738
-0.0006
-0.0004
-0.0007
-0.0015
-0.0010
-0.0018
0
0
0
Post-painted
6. HD Terne
7. HD Tin-Zinc
8. HDA?
9. Ferritic
Stainless
0
0
0
0
0
0
0
Bare Steels
* No painted surface in contact with fuel.
EXHIBIT 30. Weight changes for the fuel test lids after the maximum exposure to the fuel vapor of 39
weeks.
The weight changes for both cups and lids were extremely small - in general, less than 0.01 percent although for the pre-painted HDGA (#3), weight losses were 0.12 and 0.13 percent for the cups and
lids, respectively. The very low weight losses confirm the very slight corrosion observed by visual
inspection. No pits were observed in any material after any exposure.
- 36 -
SUMMARY OF RESULTS
The results of external corrosion testing are reviewed in relation to the two specific tests which were
conducted, as follows:
Neutral Salt Spray Test Results
The results obtained from qualitative and quantitative evaluations indicated that the corrosion was variable
across different regions of the specimens and was not severe enough to cause perforation (failure). In fact, no
pits deeper than 0.1mm were observed for any materials. The complete results are best reviewed by category
of the steel systems.
Pre-Painted Steels
For the most part, the steels showed only slight or no corrosion. However, there was modest white
rust at the dome, scribe and chip area of pre-painted HDGA #3 after 2000 hours of exposure.
The weight losses for all the pre-painted steels were low (0.17 to 1.12%) compared with the bare steel
test validation sample (12.9 to 13%). Despite the fact that there was some paint chipping for all prepainted samples, (except the inorganic coated stainless (#5)), which exposed the metallic coating, no
corrosion pits deeper than 0.1mm were found. None of the pre-painted samples showed any creepback
at the scribe line.
Post-Painted Steels
Although all of these steels performed satisfactorily in that no perforation occurred (in fact, no pits
deeper than 0.1mm were observed), the relative performance depended on the efficiency of the paint
coatings. For example:
- the thick paints (350-370µm) of the HD Terne and HD Tin-Zinc steels (#6 and #7) showed
excellent resistance to chipping, almost no visible corrosion, very low weight losses (.01 to
0.04%) and no creepback.
- the HD Aluminized steel (#8) showed severe loss of adhesion of the thin paint film (150µm) after
gravel impact and 1500 and 2000 hours exposure. As a result, some pronounced red rusting (as
shown in EXHIBIT 31) occurred at the dome, chip and field areas and extensive creepback was
observed. Despite this, the base material showed only 2% weight loss and no pits deeper than
0.1mm.
- the 436L stainless steel (#9) showed extensive adhesion loss of the thin (20µm) paint after gravel
impact, but no creepback at the scribe line, only a small overall weight loss (0.7%) and no pits
deeper than 0.1mm.
Bare Steel
The bare 304L steel showed some local red rusting, but a low weight loss (0.33% after 2000 hours
exposure). The visual ratings and photographs showed that most of the corrosion occurred on the
flange (top and bottom) near the weld and the gravel area (EXHIBIT 32). However, no pits deeper
than 0.1mm were observed even at the weld area, thus, satisfactory performance was shown even
after 2000 hours exposure.
All results for the above steel categories are summarized in tabular form in EXHIBIT 33.
- 37 -
SUMMARY OF RESULTS
EXHIBIT 31. Moderate to pronounced red and
white rusting of HDAl (#8) post-painted with thin
paint film - (Photo ID #092000nss aft) after 2000
hours Neutral Salt Spray exposure.
PRE-PAINTED STEELS
Visual Evaluation
In general, only slight or no
corrosion
• Modest white rust at dome,
scribe and chip area of HDGA
#3
Weight loss
Low losses
• Max. loss (1.1%) for HDAl #4
EXHIBIT 32. Local red rusting in the 304L stainless
steel #10 after 2000 hours of Neutral Salt Spray
Exposure (Photo ID #102000nss aft) after 2000 hours
Neutral Salt Spray exposure.
POST-PAINTED STEELS
BARE STEEL
Corrosion and paint adhesion
depended on paint film thickness.
• For materials with thick paints
(HD Terne #6 and HD Tin-Zinc
#7) no visible corrosion and
excellent chip resistance.
• For materials with thin paints
(HDAl #8 & 436L #9) showed
severe paint loss, modest to
pronounced rust for HDAl #8
but no rust for 436L #9.
Local red rusting for 304L
• flange near weld
• gravel area
Low losses
• Max. weight losses for 436L #9
(0.7%) and HDAl #8 (2.0%)
likely related to paint loss.
Low loss (0.2%) for 304L
All steel categories showed low losses compared with 3% for bare carbon steel.
Creepback at scribe
None
Severe for HDAl #8
Pit depth (deeper than 1mm)
None
None
Chip rating in gravel area
Moderate chipping (10-49 chips,
less than 1mm) and down to the
metallic coating for epoxy prepaints (#1 to #4).
No chipping of the inorganic
coated 304L #5 steel.
——
None
No chipping for thick-paint
samples (HD Terne #6 & HD TinZinc #7)
Moderate chipping & 1-3mm chip
size for 436L #9
Severe blistering of HDAl #8
——
EXHIBIT 33. Summary of NEUTRAL SALT SPRAY TEST results (after 2000 hours exposure).
- 38 -
SUMMARY OF RESULTS
Cyclic Corrosion Test Results
As with the Neutral Salt Spray results, the Cyclic Corrosion test results showed that corrosion was variable
across the different regions of the individual specimens and not serious enough to cause failure (perforation).
Of interest is the comparison of weight losses for bare steel control coupons after exposure in the the Cyclic
test (after 80 cycles) and in the Neutral Salt Spray test (2000 hours). The former showed a loss of 76%,
whereas, the later was 12.9%. This indicates the greater corrosion severity of the Cyclic test.
For the test materials, it was difficult to see definitive trends in any of the weight change data (EXHIBIT 20)
because in many cases there were gains (up to 2.49% for the bare Austenitic 304L steel) and losses (up to
2.42% for the Ferritic 436L steel, which was likely due to paint loss and not due to steel corrosion). The fact
that these changes were small compared with a reference weight loss of 76% for bare steel after only 80
cycles, indicates that very little steel corrosion weight loss occurred for all test materials. The significance of
the results is best discussed by the category of steel systems.
Pre-Painted Steels
The visual ratings of corrosion (EXHIBITS 18 and 19) for the most part showed either none, slight or
moderate corrosion for most locations of the pre-painted materials. However, the EG Zn-Ni #1
material showed moderate to pronounced red rust at the weld area after 160 cycles (see EXHIBIT 34).
All materials showed zero creepback at the scribe line, but some pits were observed after 80 and 120
cycles for the EG Zn-Ni + Cr6 (#1) and the HD Aluminized steels. However, the pits in the gravel
impact area were well below the perforation level.
The fact that some materials showed no pits after 160 cycles exposure indicates that pitting may
have been more dependent on the variability of the gravel impact than on the length of cyclic
corrosion exposure. The gravelometer results showed some paint chipping for all pre-painted
samples, but the frequency of the chips was moderate (10 - 49) and the size of chips was, in general,
low (<1mm to 3mm). For the epoxy pre-painted materials (#1-#4), the chipping occurred early
(after 20 cycles) but did not change significantly after longer cycle exposures.
EXHIBIT 34. Moderate to pronounced red rusting at the weld area of pre-painted EG Zn-Ni #1 after
160 cycles in the Cyclic Corrosion Test (Photo ID #01 J2334-160bef.2)
- 39 -
SUMMARY OF RESULTS
Post-Painted Steels
Those materials having thick post-paint films, i.e., HD Terne (#6), HD Tin-Zinc (#7) had no visual
corrosion at any location for all exposures. The thinner paint coating (150µm) on the HD
Aluminized steel (#8) had red rusting at the flange and weld after 160 cycles (see EXHIBIT 35) but
almost no rusting at other areas. For the Ferritic 436L material, no corrosion was observed despite a
pronounced adhesion loss of the zinc-rich paint.
The extent of creepback at the scribe line generally paralleled the visual observations - no
creepback for the heavily painted materials (#6 and #7), small amounts for the HD Aluminized (#8)
and significant amounts for the Ferritic 436L (#9), which had substantial paint adhesion loss. The
variations in paint adhesion performance accounted for the difference in the gravelometer chip
ratings:
- no chips for the HD Terne and HD Tin-Zinc materials (up to 370µm thick paint films)
- some chipping for the HD Aluminized steel (150µm paint)
- extensive chipping for the Ferritic 436L steel (20µm paint)
No pits (deeper than 0.1mm) were observed for any post-painted material at any location for
exposures through 160 cycles.
Bare Steel
For the most part, very minor visual
ratings of corrosion (none to slight) were
shown by the Austenitic 304L (#10) for
exposures through 160 cycles. Some
moderate red rusting was observed at
the weld area after 160 cycles (see
EXHIBIT 36).
The Cyclic Corrosion Test results are summarized
in EXHIBIT 37.
EXHIBIT 35. Moderate to pronounced red
rusting at the flange and weld area of thin
(150µm) post-painted HDAl #8 steel after
160 cycles in the Cyclic Corrosion Test.
(Photo ID #09 J2334-160bef.2)
EXHIBIT 36. Localized red rusting at the
weld of the 304L stainless steel (#10)
after 160 cycles in the Cyclic Corrosion Test.
(Photo ID #10 J2334-160bef.2)
- 40 -
SUMMARY OF RESULTS
PRE-PAINTED STEELS
Visual Evaluation
In general, none to moderate
corrosion observed
• Moderate to pronounced red
rust occurred at weld for EG
Zn-Ni #1 and at scribe for EG
Zn-Ni #2
Weight loss
Very low weight losses
(0 – 0.55%)
POST-PAINTED STEELS
BARE STEEL
Corrosion performance varied
according to thickness and adhesion
of paint films
• None to slight red rust (scribe)
for thick paints (HD Terne #6 &
HD Tin-Zinc #7)
• Moderate to pronounced red
rust at flange & weld for thinpaint HDAl#8
• No rust for 436L #9
None to slight variable red rust in
most locations and moderate rust at
weld for 304L #10
Max. weight loss (2.42%) shown by
436L #9, but probably due to paint
loss
No weight loss
The weight losses of all materials after 160 cycles was very low compared
with 76% loss for bare carbon steel after only 80 cycles exposure.
Creepback at scribe
None
Pit depth (deeper than 0.1mm)
0.1 to 0.2mm single pits observed in
gravel area of EG Zn-Ni #1 & #2 (after
80 & 120 cycles)
0.4mm single pits observed in gravel
area of HDAl #4 (after 80 & 120
cycles)
No pits observed for 160 cycle
exposure specimens.
Chip rating in gravel area
Moderate chipping (10-49 chips, less
than 1mm) and down to metallic
coating for epoxy pre-painted steels
(#1 to #4).
Moderate chipping (10-74 chips,
<1mm to 3mm) for inorganic painted
304L #5.
——
None for materials having thick paint
films (HD Terne #6 & HD Sn-Zn #7)
Moderate to severe for thin paint
films (HDAl #8 * 436L #9)
None
None
No chipping for HD Terne #6 & HD
Tin-Zinc #7
Moderate chipping (50-74 chips, 36mm) for HDAl #8
Severe chipping (100-159 chips, 36mm) for 436L #9
——
* The un-painted surface was in contact with the fuel (See EXHIBIT 25)
EXHIBIT 37.
Summary of CYCLIC CORROSION TEST results (after 160 cycles exposure).
Internal (Fuel) Corrosion Test Results
The visual ratings of cups and lids (shown in EXHIBITS 26-28) showed pronounced white residue only
at the fuel- vapor interface for the post-painted and bare steel categories. For all steels in these categories, the
fuel and vapor impinged on either a treated metallic coating or the bare steel surfaces (430L Ferritic
stainless #9 and 340L Austenitic stainless #10). As a consequence, a ring of attack occurred at the fuelvapor interface - in some cases it appeared as an 'etched' surface and in others a 'film-like' deposit. For the
pre-painted materials where the pre-paint was in contact with the fuel and vapor, no ring or concentrated
attack was observed at the fuel-vapor interface. Either visual ratings of 'none,' 'slight' or 'moderate' were
observed for all specimens that contacted either the fuel (base of cups) or vapor (cup walls and lids).
The very small weight losses (less than 0.12% for cups and 0.13% for lids) after 39 weeks of exposure confirm
that only minor corrosion, cosmetic in nature, took place. A photograph of the pre-painted HDGA #3 which
had the largest weight loss (0.12 to 0.13%) is shown in EXHIBIT 38. In fact, where some corrosion products
were observed, they were so slight that no scrapings could be procured for a chemical analysis. No pits
(deeper than 0.1mm depth) were observed in any of the materials.
The results of the Internal (Fuel) Corrosion tests are summarized in EXHIBIT 39.
- 41 -
SUMMARY OF RESULTS
EXHIBIT 38. Fuel cups and lids of pre-painted HDGA #3 after 39 weeks exposure to aggressive CE10A
fuel.
PRE-PAINTED STEELS
POST-PAINTED STEELS
BARE STEEL
Visual Evaluation
For all materials, there was no evidence of ‘corrosion’ except a white residue was observed to varying extents,
but largely at the fuel-vapor interface. (The extent of the residue was insufficient to conduct an analysis.)
No white residue in fuel and
interface areas.
Slight residue in vapor area
Slight to moderate white residue
in fuel and vapor areas.
Pronounced residue at fuel-vapor
interface.
No residue in fuel and vapor
areas.
Pronounced residue at fuel-vapor
interface for 304L #10.
Weight loss
Very minor losses generally for
cups & lids
• Max. weight loss of 0.13%) for
HDAGl #3
Very minor weight losses
generally for cups and lids
• Max. weight loss of <0.04% for
HD Terne #6
No weight loss.
Pit depths (deeper than 0.1mm)
None
None
None
** The un-paid surface was in contact with the fuel (See EXHIBIT 25)
EXHIBIT 39.
Summary of INTERNAL (FUEL) CORROSION TEST results (after 39 weeks exposure).
- 42 -
CONCLUSIONS
Simulative External Corrosion Testing, by Neutral Salt Spray and Cyclic Corrosion tests, of 10 different
steel systems has shown that:
- No perforation (failure) was observed, either after 2000 hours Salt Spray exposure or 160 cycles of
Cyclic exposure (simulating 20 years of fuel tank life), in any of the steel systems.
- The extent of corrosion varied according to the location on the specimen (dome, scribe line, weld,
and gravel impact area) and from steel to steel. However, these variations did not threaten
perforation (failure) in any of the systems. (The maximum pit depths were 20 to 40% of steel
thickness.) Furthermore, these variations were not of such significance to be able to rate one
steel system over another.
- The integrity of the paint systems varied according to the thickness of the paint.
- Those steels (EG Zn-Ni and HD Aluminized) pre-painted with thin epoxy films (9µm) and the
Austenitic 304L steel + Neukote inorganic film (17µm) showed small amounts of paint chip loss after
initial gravel impacts, but did not deteriorate after additional gravel impacts and exposures. Those
post-painted steels (HD Terne and HD Tin-Zinc) having thick acrylic and top coat paints (up to 370
µm) showed no paint loss by chipping or creepback at the scribe line. Those steels post-painted with
thinner films (i.e., the 150µm alkyd paint on HD Aluminized steel and the 20µm zinc-rich paint on
Ferritic 436L steel) had adhesion losses (after gravel impact and from creepback at the scribe line)
proportional to their coating thicknesses. This suggests that the thickness of these paint films could
be increased to further improve paint integrity which depends on the combination of coating and
paint system.
- The early withdrawal of two additional steel systems from external corrosion testing, because of
inadequate paint film thicknesses, indicates the severity of the external corrosion tests employed.
Simulative Internal Corrosion Testing of sealed cups assembled from the 10 steel systems and exposed to
an aggressive alcohol-containing gasoline (CE10A) showed only minor corrosion even after exposures of 39
weeks (representing 15-year fuel tank life). Where some corrosion occurred, there was insufficient reaction
product to enable an analysis to be conducted. No pitting (deeper than 0.1mm depth) was observed in any of
the steel systems regardless of different locations in the cups which allowed either full contact with the fuel,
contact at the fuel-vapor interface or full vapor contact.
As a result of the above specific conclusions, it is expected that all of the special steel systems tested in this
study will resist perforation corrosion (in the severe external environments experienced by automobile fuel
tanks) for up to 20 years. Additionally, it is expected that all of the steel systems tested in this study will resist
corrosion from an aggressive fuel such as CE10A for at least 15 years. Thus, it is fully anticipated that all of
the systems will meet the 15-year durability requirements of California's Air Resources Board.
All of the steel systems tested in this work are commercially available from the worldwide steel industry. The
selection of one steel system over another will depend on factors beyond corrosion resistance. These may
include:
- the manufacturing approach favored by the automakers (i.e., use of pre-painted steels, post-painting
or use of bare steels)
- material and manufacturing costs
- inherent formability and weldability of the steels
- forming and welding equipment available
The above factors are beyond the scope of this report and specific selection and application criteria should
be discussed with steel suppliers.
- 43 -
REFERENCES AND NOTES
[1] F.W. Lutze, D.C. McCune, J.R. Schaffer, K.A. Smith, L.S. Thompson, and H.E. Townsend,
“Interlaboratory Testing to Evaluate improvements in the precision of the SAE J2334 Cyclic
Corrosion Test,” Proceedings of the Fifth International Conference on Zinc and Zinc Alloy Coated
Steel Sheet, Centre for Research in Metallurgy, Brussels, Belgium, (June 2001)
[2] F.W. Lutze, D.C. McCune, H.E. Townsend, K.A. Smith, R.J. Shaffer, L.S. Thompson, and H.D.
Hilton,“The Effects of Temperature and Salt Concentration on the Speed of the SAE J2334 Cyclic
Corrosion Test,” Proceedings of the European Corrosion Congress, London, (2000)
[3] R.J. Shaffer, “Practical Test Results Using the SAE J2334 Accelerated Corrosion Test,” Proceedings of the
European Corrosion Congress, London, (2000)
[4] Dennis Davidson, et al, “Perforation Corrosion Performance of Autobody Steel Sheet in On-Vehicle
and Accelerated Tests,” SAE 2003-01-1238
[5] “Standard Practice for Operating Salt Spray (Fog) Apparatus,” ASTM Designation: B117-02
[6] “Cosmetic Corrosion Lab Test,” SAE J2334 (Revised October 2002)
[7] “Test for Chip Resistance of Surface Coatings,” SAE J400 (Revised 2002-11)
[8] “Gasoline, Alcohol and Diesel Fuel Surrogates for Materials Testing,” SAE J1681 (Rev. Jan. 2000)
[9] “Recommended Methods for Conducting Corrosion Tests in Gasoline/Methanol Fuel Mixtures,”
SAE &1747 (Dec. 1994)
[10] “Standard Test Method for Ball Punch Deformation of Metallic Sheet Material,” ASTM Designation:
E653-84 (Re-approved 2000)
[11] “Standard Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive
Environments,” ASTM Designation: D1654-00
[12] For the first 4-week exposure to fuel, Viton A was used for the gasket and some slight degradation of
the gasket was observed. Subsequently, for the remaining exposures (4 to 39 weeks) Viton F was used
and no degradation occurred.
[13] A pre-trial of 2 months (2 fuel loadings) indicated no loss of fuel after each of the 2 four-week exposures.
- 44 -
ACKNOWLEDGMENTS
The guidance and input received from several automakers (General Motors Corporation, Ford Motor
Company, DaimlerChrysler Corporation, Nissan, Toyota, FHI-Subaru, Fiat, Jaguar, and VW) concerning
the corrosion tests, methodology, specimen configuration, and materials is greatly appreciated. In
particular, the assistance from Martin Stephens and Trevor Enge (DaimlerChrysler), Jola Lott, Li Hussain
and Jim Oldfield (Ford), Peter Nguyen (GM), and Jon Sussman (Nissan) is gratefully acknowledged.
Special thanks are due to Frank Topolovec (Ford) for welding many of the External Test specimens and to
James Layland and Elmer Wendell of Homer Research Laboratories, Bethlehem Steel (now International Steel
Group) for forming the domes of the specimens, as well as for forming the cups and cutting the lids for the
Internal Fuel Test assemblies and coordinating the supply of all samples to ACT Laboratories.
Significant technical contributions, as part of early participation in the Corrosion Evaluation Team by
Stavros Fountoulakis and Steve Jones of Bethlehem Steel (now International Steel Group), Bruce Hartley
(then of National Steel), Laurent Dallemagne (Arcelor), Art Coleman (then of J & L Specialty Steel), and
Juergen Froeber (TKS) are acknowledged and appreciated.
The Corrosion Evaluation Team of SASFT is grateful to ACT Laboratories for their diligent testing and
communications. In particular, Julie Piper, Frank Lutze and Kevin Wendt were of key help in conducting
this program.
Finally, those special experts and technicians within the steel companies who provided valuable
information and guidance is greatly appreciated.
- 45 -
LIST OF ATTACHMENTS
PHOTO LIBRARY
Listing 1: Neutral Salt Spray – photo identification codes
Listing 2: Cyclic Corrosion – photo identification codes
Listing 3: Fuel Test – photo identification codes
APPENDIXES
Number
Description
1.
Reference information supporting the value of the J2334 Cyclic Test
2.
Visual ratings of rust after 2000 hours in the Neutral Salt Spray Test.
3.
Weight change of steel materials after 2000 hours exposure in the Neutral Salt Spray Test.
4.
Weight loss of test validation coupons in the Neutral Salt Spray Test.
5.
Creepback from scribe line and maximum pit depths for steels after exposure of 2000 hours in the
Neutral Salt Spray Test.
6.
Gravelometer chip ratings of steel test materials after 500, 1000, 1500 and 2000 hours exposure in
the Neutral Salt Spray Test.
7.
Visual ratings of corrosion severity after 80 cycles in the Cyclic Corrosion Test.
8.
9.
10.
Weight-change data for steel test materials and bare cold-rolled steel samples after 80 cycles
exposure in the Cyclic Corrosion Test.
11.
12.
13.
Weight loss of bare cold-rolled steel control samples after 80 cycles exposure In the Cyclic
Corrosion Test.
14.
Creepback and maximum pit depths for steel test materials after 80 cycles exposure in the Cyclic
Corrosion Test.
15.
Corrosion Test.
16.
Corrosion Test.
46
17.
Gravelometer chip ratings for the 80-cycle exposure set of steel test materials.
18.
19.
20.
Extent of corrosion (white residue) and observations after 4 weeks in the Fuel Test.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
Actual weights of fuel test cups after 0 to 39 weeks exposure in the Fuel Test.
31.
Weight changes of fuel test cups after 4 to 39 weeks exposure in the Fuel Test.
32.
Actual weights of lids after 0 to 39 weeks exposure in the Fuel Test.
33.
Weight changes of lids after 4 to 39 weeks exposure in the Fuel Test.
47
PHOTO LIBRARY – LISTING 1
Neutral Salt Spray Test Specimens.
(for photos see file: Photo Library-Neutral Salt Spray)
1-A
ID#
Material
Pre-painted steels
Photo Code
1
EG Zinc-Nickel
(with Cr6)
2
EG Zinc-Nickel
(no Cr6)
3
HDGA (Zn-Fe)
(no Cr6)
4
HD Aluminized
(no Cr6)
5
Austenitic 304L with
Neukote
#01 NSSi
#01 1000 NSS I
#01 1000 NSS F
#01 2000 NSS BEFORE
#01 2000 NSS AFTER
#02 NSS i
#02 1000 NSS I
#02 1000 NSS F
#02 2000 NSS BEFORE
#02 2000 nss aft
#03 NSSi
#03 1000 NSS i
#03 1000 NSS F
#03 2000 hr. NSS bef
#03 2000 hr. NSS aft
#04 NSSi
#04 1000 NSS I
#04 1000 NSS F
#04 2000 NSS BEFORE
#04 2000 nss aft
#11 NSSi
#11 1000 NSS I
#11 1000 NSS F
#11 2000 NSS BEFORE
#11 2000 nss aft
Exposure
(hrs)
0
1000
1000
2000
2000
0
1000
1000
2000
2000
0
1000
1000
2000
2000
0
1000
1000
2000
2000
0
1000
1000
2000
2000
Condition
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
48
(continued)
Neutral Salt Spray Test Specimens.
(for photos see file: Photo Library-Neutral Salt Spray)
1-B
ID#
in
Report
Post-painted steels
Material
6
HD Terne
7
HD Tin-Zinc
8
HD Aluminized
9
Ferritic 436L
Stainless
Photo ID Code
#05 NSSi
#05 1000 NSS I
#05 1000 NSS F
#05 2000 NSS BEFORE
#05 2000 nss aft
#06 NSSi
#06 1000 NSS I
#06 1000 NSS F
#06 2000 NSS BEFORE
#06 2000 nss aft
#09 NSSi
#09 1000 NSS I
#09 1000 NSS F
#09 2000 NSS BEFORE
#09 2000 nss aft
#13 NSSi
#13 1000 NSS I
#13 1000 NSS F
#13 2000 NSS BEFORE
#13 2000 nss aft
1-C
ID#
in
Report
10
Material
Austenitic 304L
Stainless
Exposure
(hrs)
0
1000
1000
2000
2000
0
1000
1000
2000
2000
0
1000
1000
2000
2000
0
1000
1000
2000
2000
Condition
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
Bare steels
Photo ID Code
#10 NSSi
#10 1000 NSS I
#10 1000 NSS F
#10 2000 NSS BEFORE
#10 2000 nss aft
Exposure
(hrs)
0
1000
1000
2000
2000
Condition
After gravel
Before gravel
After gravel
Before cleaning
After cleaning
(continued)
49
Cyclic Corrosion Test Specimens.
(for photos see file: Photo Library-Cyclic Test)
2-A
ID#
in
Report
1
2
3
Test
Material
EG ZincNickel
+ Cr6
EG ZincNickel
- Cr6
HDGA (ZnFe)
- Cr6
Pre-painted steels
Photo ID Code
#01 J2334-160i
Exposure,
cycles
0
Condition
After gravel
#01 J2334-120 bef
#01 J2334-120 bef-2
120
120
#01 J2334-120 aft
#01 J2334-160 bef
#01 J2334-160 bef-2
120
160
160
#01 J2334-160 aft
#02 J2334-160i
160
0
#02 J2334-120 bef
#02 J2334-120 bef-2
120
120
#02 J2334-120 aft
#02 J2334-160 bef
#02 J2334-160 bef-2
120
160
160
#02 J2334-160 aft
#03 160A&B @ Initial
160
0
#03 120A&B @120+J400
#03 120A&B @ 120 cycles final
120
120
#03 120A&B @ 120 cycles final 2
120
#03 160A&B @160 cycles final
160
After gravel, before cleaning
After cleaning
(flange view)
After cleaning
(flange view)
After cleaning (flange view)
#03 160A&B @160 cycles final 2
160
After cleaning (flange view)
(flange view)
After cleaning
(flange view)
After cleaning
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
After gravel
50
2-A
ID#
in
Report
4
5
Test
Material
HD
Aluminized
- Cr6
Austenitic
Stainless
and
Neukote
Pre-painted steels (continued)
Photo ID Code
#04 J2334-160i
Exposure,
cycles
0
#04 J2334-120 bef
#04 J2334-120 bef-2
120
120
#04 J2334-120 aft
#04 J2334-160 bef
#04 J2334-160 bef-2
120
160
160
#04 J2334-160 aft
160
#11 J2334-160i
0
#11 J2334-120 bef
#11 J2334-120 bef-2
120
120
#11 J2334-120 aft
#11 J2334-160 bef
#11 J2334-160 bef-2
120
160
160
#11 J2334-160 aft
160
Condition
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
(continued)
51
(continued)
2-B
ID#
in
Report
6
7
8
Test
Material
HD Terne
HD Tin-Zinc
HD Aluminized
Post-painted steels
Photo ID Code
#05 J2334-160i
Exposure,
cycles
0
#05 J2334-120 bef
#05 J2334-120 bef-2
120
120
#05 J2334-120 aft
#05 J2334-160 bef
#05 J2334-160 bef-2
120
160
160
#05 J2334-160 aft
#06 J2334-160i
160
0
#06 J2334-120 bef
#06 J2334-120 bef-2
120
120
#06 J2334-120 aft
#06 J2334-160 bef
#06 J2334-160 bef-2
120
160
160
#06 J2334-160 aft
#09 J2334-160i
160
0
#09 J2334-120 bef
#09 J2334-120 bef-2
120
120
#09 J2334-120 aft
#09 J2334-160 bef
#09 J2334-160 bef-2
120
160
160
#09 J2334-160 aft
160
Condition
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
(continued)
52
(continued)
2-B
ID#
in
Report
9
Test
Material
Ferritic
Stainless
Post-painted steels (continued)
Photo ID Code
#13 J2334-160i
Exposure,
cycles
0
#13 J2334-120 bef
#13 J2334-120 bef-2
120
120
#13 J2334-120 aft
#13 J2334-160 bef
#13 J2334-160 bef-2
120
160
160
#13 J2334-160 aft
160
2-C
ID#
in
Report
10
Test
Material
Austenitic
Stainless
Condition
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
Bare steels
Photo ID Code
#10 J2334-160i
Exposure,
cycles
0
#10 J2334-120 bef
#10 J2334-120 bef-2
120
120
#10 J2334-120 aft
#10 J2334-160 bef
#10 J2334-160 bef-2
120
160
160
#10 J2334-160 aft
160
Condition
After gravel
(flange view)
After cleaning
(flange view)
After cleaning
(continued)
53
Fuel Test Specimens.
(for photos see file: Photo Library-Fuel Test)
3A
ID#
in
Report
1
2
3
4
5
Pre-painted steels
Test Material
EG Zinc-Nickel
+ Cr6
EG Zinc-Nickel
- Cr6
HDGA (Zinc-Iron)
- Cr6
HD Aluminized
+ Cr6
Austenitic 304L
Stainless with
Neukote
Photo ID Code
#01 Initial
Fuel Exposure
Time, weeks
0
#01 @ 28 weeks
28
#01 @ 39 weeks
39
#02 Initial
0
#02 @ 28 weeks
28
#02 @ 39 weeks
39
#03 Initial
0
#03 @ 28 weeks
28
#03 @39 weeks
39
#04 Initial
0
#04 @ 28 weeks
28
#04 @ 39 weeks
39
#11 Initial
0
#11 @ 28 weeks
28
#11 @ 39 weeks
39
54
(continued)
Fuel Test Specimens.
(for photos see file: Photo Library-Fuel Test)
3-B
ID#
in
Report
6
7
8
9
Post-painted steels
Test Material
HD Terne
HD Tin-Zinc
HD Aluminized
Ferritic 436L
Stainless
3C
ID#
in
Report
10
Test Material
Austenitic 304L
Stainless
Photo ID Code
#05 Initial
Fuel Exposure
Time, weeks
0
#05 @ 28 weeks
28
#05 @ 39 weeks
39
#06 Initial
0
#06 @ 28 weeks
28
#06 @ 39 weeks
39
#09 Initial
0
#09 @ 28 weeks
28
#09 @ 39 weeks
39
#13 Initial
0
#13 @ 28 weeks
28
#13 @ 39 weeks
39
Bare steels
Photo ID Code
#10 Initial
Fuel Exposure
Time, weeks
0
#10 @ 28 weeks
28
#10 @ 39 weeks
39
PHOTO LIBRARY – LISTING 3 (continued)
55
APPENDIX 1
APPENDIX 1. Published data concerning the practical use and predictability of the Cyclic Corrosion test for
automobile corrosion resistance were selected data from:
“Perforation Corrosion Performance of Auto Body Steel Sheet in On-Vehicle and Accelerated Tests,”
Dennis Davidson, Larry Thompson, Frank Lutze, Butch Tiburcio, Kevin Smith, Cindy Meade, Tom Mackie,
Duncan McCune, Herb Townsend, Rebecca Tuszynski, and Martin Stephens, SAE 2003-01-1238
56
APPENDIX 1 (cont.)
57
APPENDIX 2
ID
Pre-painted Steels
1- EG Zinc-Nickel
with Cr6
Dome
White Red
2- EG Zinc-Nickel
without Cr6
3 HDGA without Cr6
4- HDAl
with Cr6
5- Austenitic
304L +
Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aℓ
9- Ferritic
436L
Bare steel
10- Austenitic
304L
Scribe
White Red
Chip
White Red
Field
White Red
Region of Specimen
Flange
Flange (Under Clip)
Weld
White Red
White
Red
White Red
S
S
S
M
M
M
P
P
S
M
M
M
N
N
N
N
N
N
S
N
S
S
S
S
P
S
S
N
N
N
S
S
S
S
S
S
P
P
P
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
P
P
P
S
S
S
N
N
N
N
N
N
N
N
N
S
S
S
N
N
N
N
N
N
S
S
S
S
S
S
P
P
P
S
S
S
N
N
N
N
N
N
N
N
N
S
S
S
S
N
N
N
N
N
N
N
N
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
N
N
N
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
S
N
N
N
N
N
N
N
N
N
N
S
S
N
S
N
N
N
N
N
N
N
N
N
N
N
S
N
N
N
N
N
N
N
N
N
N
S
M
S
M
M
M
N
N
N
N
N
N
P
P
P
N
N
N
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
P
P
S
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
P
P
P
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
P
P
P
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
M
M
M
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
M
M
M
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
S
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
S
N
N
N
S
S
S
N
N
N
S
S
S
Key
N
S
M
P
=
=
=
=
Weld (Under Clip)
White
Red
None: no corrosion
Slight: Less than approximately 15% corrosion
Moderate: Approximately 15 – 30% corrosion
Pronounced: Greater than approximately 30% corrosion
APPENDIX 2. Visual ratings of rust after 2000 hours exposure in the Neutral Salt
Spray Test. (Rust staining is not included in the ratings)
Loss of Adhesion
Note 1
Note 1
Note 2
Note 2
Notes A,C,D
Notes A,B,D
Notes A,B,D
Note 3
Note 3
Note 3
Note 4
Note 4
Note 4
Note 5
Notes 5 & 6
Note 5
Notes
1. Moderate loss of adhesion in flange area
A: Slight adhesion loss at dome
2. Pronounced adhesion loss in flange area
B: Slight adhesion loss at flange/clip
3. Pronounced adhesion loss in flange area
C: Moderate adhesion loss at flange/clip
4. Pronounced loss of adhesion/blistering in all areas
D: Pronounced blistering at flange/clip
5. Pronounced loss of adhesion on flange underside and moderate loss of adhesion at scribe
58
6. Moderate loss of adhesion at chip area
APPENDIX 3
Initial Weight
ID
Pre-painted steels
1- Eg Zinc-Nickel
338.4 g
1- + Cr6
338.4
1339.3
Final Weight
Weight loss (gain), g
Specific Average
Average Weight Loss
(Gain) %
337.7 g
337.8
338.9
0.7
0.6
0.4
0.6
0.2
0.9
0.3
(0.5)
(0.2)
2- Eg Zinc-Nickel
2- - Cr6
2-
347.7
348.3
349.2
347.6
347.0
348.0
0.1
1.3
1.2
3- HDGA
3- - Cr6
3-
258.8
266.3
264.0
259.3
267.0
264.2
(0.5)
(0.7)
(0.2)
4- HDAl
4- + Cr6
4-
295.2
290.0
291.8
291.0
287.9
288.3
4.2
2.1
3.5
3.3
1.1
5- Austenitic
5- 304L
5- + Neukote
294.4
297.3
298.2
292.8
295.6
296.3
1.6
1.7
1.9
1.7
0.6
Post-painted steels
6- HD Terne
66-
314.9
313.6
319.6
314.9
313.6
319.5
0.0
0.0
0.1
0.0
0.0
7- HD Tin-Zinc
77-
320.3
326.3
322.8
320.5
326.2
322.9
0.2
0.1
0.1
0.1
0.0
8- HD Aluminum
88-
288.6
287.8
290.6
281.8
283.2
284.6
6.8
4.6
6.0
5.8+
2.0
9- Ferritic
9- 436L
9-
265.6
265.2
271.2
264.1
262.6
269.7
1.5
2.6
1.5
1.9+
0.7
Bare Steel
10- Austenitic
10- 304L
10-
290.5
293.0
292.7
289.8
292.3
291.9
0.7
0.7
0.8
0.7
0.2
+
Weight losses were likely the result of paint loss.
APPENDIX 3. Weight change of steel materials after 2000 hours exposure in the Neutral Salt Spray Test.
59
APPENDIX 4
Exposures
500
Steel 1
Steel 2
Zinc 1
Zinc 2
g
0.9000
0.8197
2.1446
3.2567
%
2.94
2.68
30.97
46.65
1000
g
%
1.9058
6.22
1.9323
6.33
2.2287
32.08
3.3146
47.83
1500
g
%
2.8908
9.43
2.9708
9.68
3.3118
47.88
3.6249
52.10
2000
g
%
3.8758
12.6
4.0157
13.1
*
*
*
*
* Coupon disintegrated and could not be weighed.
APPENDIX 4. Weight loss of test validation coupons in the Neutral Salt Spray Test.
60
APPENDIX 5
ID
Pre-painted steels
1- EG Zn-Ni + Cr6
-
Creepback from Scribe, mm
Average
Minimum
Maximum
Maximum Pit Depth
(deeper than 0.1mm)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
2- Eg Zn-Ni - Cr6
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
3- HDGA - Cr6
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
4- HDAl + Cr6
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
5- Austenitic
- 304L +
- Neukote
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
Post-painted steels
6- HD Terne
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
7- HD Tin-Zinc
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
8- HD Aluminum
-
Full*
Full*
12.2
Full*
Full*
0.2
Full*
Full*
62.2
None Observed
None Observed
None Observed
9- Ferritic
- 436L
Bare steel
10- Austenitic
- 304L
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
None Observed
* Loss of adhesion extended to edge of specimen
APPENDIX 5. Creepback from scribe line and maximum pit depth for steels after exposure of 2000 hours in the
61
APPENDIX 6
ID
500 Hours
Loss of
Rating Adhesion
1000 Hours
Loss of
Rating Adhesion
1500 Hours
Loss of
Rating Adhesion
2000 Hours
Loss of
Rating Adhesion
Pre-painted steels
1- EG Zn-Ni
5A
5A
5A
2- EG Zn-Ni
6A
6A
6A
3A- HDGA
6A
6A
6A
4- HD Alum.
6A
6A
6A
5- Austenitic
10
- 304L +
10
- Neukote
10
MC/T*
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
None
5A
5A
5A
6A
6A
6A
5A
6A
6A
6A
6A
6A
10
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
None
5A
5A
5A
6A
6A
6A
5A
6A
6A
6A
6A
6A
10
10
10
Post-painted steels
6- HD Terne
10
10
10
7- HD Tin-Zinc 10
10
10
8- HD Alum.
4A
4A
4A
9- Ferritic
5A
- 436L
5A
5A
None
None
None
None
None
None
MC/T
MC/T
MC/T
S/T**
S/T
S/T
10
10
10
10
10
10
4A
4A
4A
4A
4A
4A
None
None
None
None
None
None
MC/T
MC/T
MC/T
S/T
S/T
S/T
10
None
10
None
10
None
10
None
10
None
10
None
10
None
10
None
10
None
10
None
10
None
10
None
No rating due to excessive blistering
"
"
"
"
"
"
"
"
5B
S/T
5B
S/T
5B
S/T
5B
S/T
5B
S/T
5B
S/T
None
None
None
10
10
10
Bare steel
10- Austenitic
- 304L
-
10
10
10
None
None
None
10
10
10
MC/T
MC/T
MC/T
MC*/T
MC*/T
MC*/T
MC*/T
MC*/T
MC*/T
MC*/T
MC*/T
MC*/T
None
None
None
5A
5A
5A
6A
6A
6A
5A
6A
6A
6A
6A
6A
10
10
10
None
None
None
10
10
10
Chip frequency
Rating numbers
0
Number of chips
>250
Loss of
adhesion
APPENDIX 6.
1
2
3
4
5
6
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
None
None
None
None
Size rating &
size range of chips
7
8
9
10
150- 100755025105-9
2-4
1
0
250
159
99
74
49
24
*MC/T denotes Metallic Coating to topcoat / **S/T denotes Substrate steel to
topcoat
A
B
C
D
<1
mm
1-3
mm
3-6
mm
>6
mm
Gravelometer chip ratings of steel system specimens after 500 hours, 1000 hours, 1500 hours, and
2000 hours exposure in the Neutral Salt Spray Test.
62
APPENDIX 7
ID
Pre-painted Steels
1- EG Zinc-Nickel
2- EG Zinc-Nickel
3- HDGA (Zn-Fe)
4- HDAl
5- Austenitic
- 304L + Neukote
Region of Specimen
Dome
Scribe
Chip
Field
Flange
Flange (Under Clip) Weld
White Red White Red White Red White Red White Red
White
Red
White Red
Weld (Under Clip)
White
Red Loss of Adhesion
S
S
S
S
M
M
S
S
N
N
S
S
N
N
S
S
S
S
N
N
S
S
S
S
S
S
S
S
N
N
N
N
S
S
P
P
S
S
N
S
S
S
S
S
M
M
S
S
N
N
S
S
S
S
S
S
N
N
S
S
S
S
S
S
M
M
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
N
N
N
N
N
M
S
N
N
N
N
S
S
N
N
M
S
N
N
S
S
N
N
N
N
S
S
N
N
N
N
M
P
N
N
S
S
N
N
S
N
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminized
9- Ferritic
- 436L
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
M
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
N
N
N
N
N
N
P
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
S
N
N
N
N
N
N
N
S
N
N
Bare steel
10-Austenitic
-304L
N
N
N
N
N
N
S
S
N
N
S
S
N
N
N
N
N
N
S
S
N
N
S
S
N
N
M
M
N
N
S
S
N
S
M
P
=
=
=
=
None: no corrosion
Note 1
Note 1
Note 2
Note 2
Note 3
Note 3
Note 1: Moderate blistering in flange area
Note 2: Moderate adhesion loss in chip area and slight loss of adhesion
in scribe area
Note 3: Moderate to Pronounced adhesion loss in all areas
APPENDIX 7. Visual ratings of corrosion severity after 80 cycles exposure in the Cyclic Corrosion Test.
63
APPENDIX 8
ID
Pre-painted Steels
1- EG Zinc-Nickel
- Cr6
2- Eg Zinc-Nickel
- Cr6
3- HDGA (Zn-Fe)
4- HDAl
- Cr6
5- Austenitic
- 304L + Neukote
Region of Specimen
Dome
Scribe
Chip
Field
Flange
Flange (Under Clip)
Weld
Weld (Under Clip)
White
Red
White Red White
S
S
S
S
M
M
S
S
N
N
S
S
S
S
S
S
S
S
N
N
S
S
S
S
S
S
S
S
N
N
S
S
S
S
P
P
S
S
S
S
S
S
S
S
M
M
S
S
N
N
S
S
S
S
S
S
N
N
S
S
S
S
S
S
M
M
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
S
S
N
N
S
S
N
N
N
N
S
S
N
N
N
N
N
N
N
N
S
S
N
N
S
S
N
N
N
S
M
S
N
N
N
N
M
M
S
N
M
S
N
N
S
S
N
N
N
N
S
S
N
N
N
N
P
P
N
N
M
S
N
N
S
S
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminized
9- Ferritic
- 436L
N
N
N
N
N
N
N
N
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
M
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
N
N
N
N
N
N
P
P
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
P
P
N
N
N
N
N
N
S
S
N
N
N
N
N
N
S
S
N
N
Bare steel
10-Austenitic
-304L
N
N
N
N
N
N
S
S
N
N
S
S
N
N
N
N
N
N
S
S
N
N
S
S
N
N
S
M
N
N
S
S
N
S
M
P
=
=
=
=
None: no corrosion
Note 1
Note 1
Note 2
Note 2
Note 3
Note 3
Note 2: Moderate adhesion loss in chip area and slight loss of
adhesion in scribe area
64
APPENDIX 9
ID
Pre-painted Steels
1- EG Zinc-Nickel
- Cr6
2- Eg Zinc-Nickel
- Cr6
3- HDGA (Zn-Fe)
4- HDAl
- Cr6
5- Austenitic
- 304L + Neukote
Region of Specimen
Dome
Scribe
Chip
Field
Flange
Flange (Under Clip)
Weld
Weld (Under Clip)
White
Red
White Red White
S
S
S
S
M
M
S
S
N
N
S
S
N
S
S
S
M
M
N
N
S
S
S
S
S
S
S
S
N
N
S
S
S
S
P
P
S
S
S
S
S
S
S
S
M
M
S
S
N
N
S
S
S
S
S
S
N
N
S
S
S
S
S
S
M
M
N
N
N
N
N
N
N
N
S
S
N
N
N
S
N
N
N
N
S
S
N
N
N
N
N
N
N
N
M
S
N
S
S
S
N
N
N
N
N
S
N
N
N
N
N
N
N
N
S
S
N
N
S
N
N
N
N
N
S
S
N
N
N
N
P
M
S
S
P
S
S
N
M
S
N
N
N
N
S
S
N
N
N
N
N
N
N
M
P
S
N
N
S
S
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminized
9- Ferritic
- 436L
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
M
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
N
N
N
N
N
N
P
P
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
S
N
N
N
N
N
N
S
S
N
N
N
N
N
N
P
P
N
N
N
N
N
N
N
S
N
N
N
N
N
N
N
S
N
N
Bare steel
10-Austenitic
-304L
N
N
S
N
N
N
S
S
N
N
S
S
N
N
N
N
N
N
S
S
N
N
S
S
N
N
M
M
N
N
S
S
N
S
M
P
=
=
=
=
None: no corrosion
Note 1
Note 1
Note 2
Note 2
Note 3
Note 3
Note 2: Moderate adhesion loss in chip area and slight loss of adhesion in
scribe area
65
APPENDIX 10
ID
Pre-painted steels
1- EG Zinc-Nickel
2- EG Zinc-Nickel
3- HDGA (Zn-Fe)
4- HDAl
5- Austenitic
- 304L + Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminum
9- Ferritic
- 436L
Bare Steel
10- Austenitic
- 304L
Control (CRS)
(6 specimens)
Initial Weight
Final Weight
Change, g
336.3
338.4
345.7
348.5
258.1
261.3
286.9
286.6
297.1
295.9
336.1
338.3
345.6
348.3
258.7
261.6
286.9
286.7
295.9
294.7
-0.2
-0.1
-0.1
-0.2
0.6
0.3
0.0
0.1
-1.2
-1.2
311.7
321.7
323.7
330.0
290.4
290.1
263.1
264.4
312.1
322.2
324.0
330.5
290.3
290.0
270.6
269.6
0.4
0.5
0.3
0.5
-0.1
-0.1
7.5
5.2
289.9
289.7
175.2
297.0
297.0
42.1
7.1
7.3
1 33.1
Average
% Change
-0.15
-0.04
-0.15
-0.04
0.5
0.2
0.05
0.02
-1.2
-0.4
0.45
0.14
0.4
0.12
-0.1
-0.03
6.35
+
2.41+
7.2+
2.48+
76.0
+
The reason for the weight increases is unclear.
APPENDIX 10. Weight change data for steel specimens and bare cold rolled steel (CRS)
control after 80-cycle exposure in the Cyclic Corrosion test.
66
APPENDIX 11
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- Cr
2- EG Zinc-Nickel
6
- - Cr
3- HDGA (Zn-Fe)
4- HDAl
- + Cr6
5- Austenitic
- 304L + Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminized
9- Ferritic
- 436L
Bare Steel
10-Austenitic
-304L
Control (CRS)
+
Initial Weight
Final Weight
Change, g
338.6
339.5
348.7
345.7
258.0
262.9
286.4
286.9
298.1
298.6
338.9
339.9
348.7
345.9
258.9
263.4
286.9
287.7
297.2
297.7
0.3
0.4
0.0
0.2
0.9*
0.5*
0.5
0.8
-0.9
-0.9
325.4
316.2
337.2
328.5
287.6
287.1
260.1
264.5
326.4
317.1
338.3
329.3
288.1
287.4
264.8
268.4
1.0
0.9
1.1
0.8
0.5
0.3
4.7
3.9
294.1
291.6
301.5
298.8
7.4
7.2
Average
% Change
0.35
0.10
0.10
0.03
0.7
0.27
0.65
0.23
-0.90
-0.30
0.95
0.30
0.95
0.29
0.40
0.14
4.30
+
1.64+
7.3+
2.49+
Coupons removed after 80 cycles
The reason for the weight increases is unclear.
*Unable to remove all corrosion products with air blow-off
APPENDIX 11. Weight change data for steel specimens after 120-cycle exposure in the Cyclic Corrosion test.
67
APPENDIX 12
ID
Pre-painted steels
1- EG Zinc-Nickel
2- EG Zinc-Nickel
3- HDGA (Zn-Fe)
4- HDAl
5- Austenitic
- 304L + Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminum
9- Ferritic
- 436L
Bare Steel
10-Austenitic
-304L
Control (CRS)
Initial Weight
Final Weight
Change, g
340.3
339.8
346.6
346.9
264.2
260.6
287.0
287.0
297.4
297.8
340.0
340.0
347.2
346.0
265.7
260.9
287.4
287.3
296.1
296.5
-0.3
0.2
0.6
-0.9
1.5
0.3
0.4
0.3
-1.3
-1.3
325.4
326.7
334.9
318.0
290.0
289.2
261.7
266.7
325.9
327.2
335.3
318.4
291.0
291.5
256.6
259.0
0.5
0.5
0.4
0.4
1.0
2.3
-5.1
-7.7
289.5
288.2
290.4
289.2
0.9
1.0
+
Average
% Loss (Gain)
0
0
-0.3
0.09
0.9
(0.3)
0.35
(0.12)
-1.3
0.55
0.5
(0.15)
0.4
(0.12)
1.65
(0.57)
-6.4
2.42
0.95
(0.33)
+
Coupons removed after 80 cycles
Weight loss is attributed to loss of the paint film.
APPENDIX 12. Weight change data for steel specimens after 160-cycle exposure in the Cyclic Corrosion test.
68
APPENDIX 13
Control
Specimen*
Initial
Weight, g
Final
Weight, g
Loss
In Weight, g
1
176.4
32.7
143.7
2
173.1
37.3
135.8
3
175.4
46.8
128.6
4
174.7
47.4
127.3
5
175.9
50.5
125.4
6
175.7
37.9
137.8
Average
175.2
42.1
133.1 (76%)
APPENDIX 13. Weight loss of bare cold rolled steel control samples after 80 cycles
exposure in the Cyclic Corrosion test.
69
APPENDIX 14
Average
Maximum Pit Depth,mm
(above 0.1mm)
Minimum
Maximum
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None observed
None observed
0.1
None observed
None observed
None observed
4- HDAl
0.0
0.0
0.0
5- Austenitic
- 304L + Neukote
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
None observed
None observed
None Observed
None Observed
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminum
9- Ferritic
- 436L
0.0
0.0
0.0
0.0
0.6
0.6
7.2
6.5
0.0
0.0
0.0
0.0
0.4
0.1
0.1
0.1
0.0
0.0
0.0
0.0
1.7
1.0
29.3
36.4
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
Bare steel
10-Austenitic
-304L
0.0
0.0
0.0
0.0
0.0
0.0
None Observed
None Observed
ID
Pre-painted steels
1- EG Zinc-Nickel
2- Eg Zinc-Nickel
3- HDGA (Zn-Fe)
-
Location of Pit
Gravel area
Other areas
Gravel area
APPENDIX 14. Creepback and maximum pit depths for steel test materials exposed for 80 cycles in the
Cyclic Corrosion test.
70
APPENDIX 15
Minimum
Maximum
0.0
0.0
0.0
0.0
0.0
0.0
2- Eg Zinc-Nickel
3- HDGA (Zn-Fe)
-
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
4- HDAl
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
0.4
No rating*
No rating*
0.0
0.0
0.0
0.0
0.1
0.1
No rating*
No rating*
0.0
0.0
0.0
0.0
ID
Pre-painted steels
1- EG Zinc-Nickel
-
5- Austenitic
- 304L + Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminum
9- Ferritic
- 436L
Bare steel
10-Austenitic
-304L
Average
0.0
0.0
0.0
0.0
0.9
0.8
No rating*
No rating*
0.0
0.0
Pit Depth and Location
(above 0.1mm)
Location of Pit
0.2
None observed
0.2
None observed
None observed
None observed
None observed
None observed
Gravel area
Other areas
Gravel area
Other areas
0.4
None observed
0.2
None observed
None Observed
None Observed
Gravel area
Other areas
Gravel area
Other areas
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
* Unable to rate due to pronounced adhesion loss.
APPENDIX 15. Creepback and maximum pit depths for steel test materials exposed for 120 cycles
71
APPENDIX 16
(deeper than 0.1mm)
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- + Cr
Average
Minimum
0.0
0.0
0.0
0.0
0.0
0.0
None observed
None observed
2- Eg Zinc-Nickel
- - Cr6
3- HDGA (Zn-Fe)
4- HDAl
- + Cr6
5- Austenitic
- 304L + Neukote
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
None observed
None observed
None observed
None observed
None observed
None observed
None Observed
None Observed
0.0
0.0
0.0
0.0
0.1
0.2
0.1
No rating*
0.0
0.0
0.0
0.0
1.0
1.4
17.6
No rating*
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
None Observed
0.0
0.0
0.0
0.0
None Observed
None Observed
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Aluminum
9- Ferritic
- 436L
Bare steel
10-Austenitic
-304L
0.0
0.0
0.0
0.0
0.4
0.6
2.5
No rating*
0.0
0.0
Maximum
* Unable to rate due to pronounced adhesion loss.
APPENDIX 16. Creepback and maximum pit depths for steel test materials exposed for 160 cycles
72
APPENDIX 17
20 Cycles
Loss of
Rating Adhesion
ID
Pre-painted steels
1- EG Zinc-Nickel 5A
MC/T*
6
5A
MC/T
- + Cr
2- EG Zinc-Nickel 5A
MC/T
6
5A
MC/T
- - Cr
3- HDGA (Zn-Fe) 6A
MC/T
6A
MC/T
4- HD Alum.
6A
MC/T
6
6A
MC/T
- + Cr
5- Austenitic
10
None
- 304L+Neukote 10
None
40 Cycles
Loss of
Rating Adhesion
60 Cycles
Loss of
Rating Adhesion
80 Cycles
Loss of
Rating Adhesion
5A
5A
5A
5A
5A
5A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
8A
6A
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
S/T**
S/T
Post-painted steels
6- HD Terne
10
10
7- HD Tin-Zinc
10
10
8- HD Alum.
5A
5A
9- Ferritic
6B
- 436L
6B
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
6B
6B
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
5C
5C
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
Bare steel
10-Austenitic
-304L
None
None
10
10
None
None
10
10
None
None
10
10
None
None
10
10
Chip frequency
Rating numbers
0
Number of chips
>250
Loss of
adhesion
1
2
3
4
5
6
Size rating &
size range of chips
7
8
9
150- 100755025105-9
2-4
1
250
159
99
74
49
24
*MC/T denotes Metallic Coating to topcoat / **S/T denotes steel to topcoat
10
A
B
C
D
0
<1
mm
1-3
mm
3-6
mm
>6
mm
APPENDIX 17. Gravelometer chip ratings for the 80 cycles exposure set of all steel specimens
73
APPENDIX 18
20 Cycles
Loss of
Rating Adhesion
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- + Cr
2- EG Zinc-Nickel
6
- - Cr
3- HDGA (Zn-Fe)
4- HD Alum.
6
- + Cr
5- Austenitic
- 304L+Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Alum.
9- Ferritic
- 436L
Bare steel
10-Austenitic
-304L
60 Cycles
Loss of
Rating Adhesion
5A
5A
5A
5A
6A
6A
6A
6A
10
10
MC/T*
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
5A
5A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
10
10
10
10
5A
5A
6B
6B
None
None
None
None
MC/T
MC/T
S/T**
S/T
10
10
10
10
6B
6B
6B
6B
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
None
None
10
10
None
None
10
10
None
None
80 Cycles
Loss of
Rating Adhesion
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- + Cr
2- EG Zinc-Nickel
6
- - Cr
3- HDGA (Zn-Fe)
4- HD Alum.
6
- + Cr
5- Austenitic
- 304L+Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Alum.
9- Ferritic
- 436L
Bare steel
10-Austenitic
-304L
40 Cycles
Loss of
Rating Adhesion
100 Cycles
Loss of
Rating Adhesion
120 Cycles
Loss of
Rating Adhesion
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
4C
5C
2C
2C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
None
None
10
10
None
None
10
10
None
None
Chip frequency
Rating numbers
Number of chips
Loss of adhesion
0
>250
1
2
3
4
5
6
7
8
9
150- 100755025105-9
2-4
1
250
159
99
74
49
24
*MC/Tdenotes Metallic Coating to topcoat / **S/T denotes steel to topcoat
Size rating &
size range of chips
10
0
A
<1
mm
B
1-3
mm
C
3-6
mm
D
>6
mm
74
APPENDIX 19
20 Cycles
Loss of
Rating Adhesion
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- + Cr
2- EG Zinc-Nickel
6
- - Cr
3- HDGA (Zn-Fe)
4- HD Alum.
6
- + Cr
5- Austenitic
- 304L+Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Alum.
9- Ferritic
- 436L
Bare steel
10- Austenitic
- 304L
40 Cycles
Loss of
Rating Failure
80 Cycles
Loss of
Rating Adhesion
5A
5A
5A
5A
6A
6A
6A
6A
10
10
MC/T*
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
5A
5A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
10
10
10
10
5A
5A
6B
6B
None
None
None
None
MC/T
MC/T
**
S/T
S/T
10
10
10
10
6B
6B
6B
6B
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
4C
4C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
None
None
10
10
None
None
10
10
None
None
10
10
None
None
100 Cycles
Loss of
Rating Adhesion
ID
Pre-painted steels
1- EG Zinc-Nickel
6
- + Cr
2- EG Zinc-Nickel
6
- - Cr
3- HDGA (Zn-Fe)
4- HD Alum.
6
- + Cr
5- Austenitic
- 304L+Neukote
Post-painted steels
6- HD Terne
7- HD Tin-Zinc
8- HD Alum.
9- Ferritic
- 436L
Bare steel
10-Austenitic
-304L
60 Cycles
Loss of
Rating Adhesion
120 Cycles
Loss of
Rating Adhesion
140 Cycles
Loss of
Rating Adhesion
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
10
10
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
None
None
5A
5A
5A
5A
4A
4A
6A
6A
6B
4A
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
2C
2C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
6B
6B
2C
2C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
4B
4B
2C
2C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
10
10
4C
4C
2C
2C
None
None
None
None
MC/T
MC/T
S/T
S/T
10
10
None
None
10
10
None
None
10
10
None
None
10
10
None
None
Chip frequency
Rating numbers
0
Number of chips
>250
Loss of adhesion
160 Cycles
Loss of
Rating Adhesion
1
2
3
4
5
6
Size rating &
size range of chips
7
8
9
150- 100755025105-9
2-4
1
250
159
99
74
49
24
*MC/T denotes Metallic Coating to topcoat / **S/T denotes steel to topcoat
10
A
B
C
D
0
<1
mm
1-3
mm
3-6
mm
>6
mm
75
APPENDIX 20
Extent of white residue
Steel ID
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
Pre-painted steel category
+6
N
N
N
N
1 – EG Zinc-Nickel (with Cr )
–
N
N
N
N
–
N
S
N
N
2 – EG Zinc-Nickel (without Cr+6)
N
N
N
N
–
N
N
N
N
–
N
N
N
N
3 – HDGA Zn-Fe (without Cr+6)
N
N
N
N
–
N
N
N
N
–
N
N
N
N
4 – HDAℓ (with Cr+6)
N
N
N
N
–
N
N
N
N
–
N
N
N
N
5 – Austenitic 304L Stainless (Neukote)
N
N
N
N
–
N
N
N
N
–
N
N
N
N
Post-painted steel category
6 – HD Terne
N
N
N
N
–
N
N
N
N
–
N
N
N
N
7 – HD Tin-Zinc
N
N
N
N
–
N
N
N
N
–
N
N
N
N
8 – HD Aluminized
N
N
N
N
–
N
N
N
N
–
N
N
N
N
9 – Ferritic 436L Stainless
N
N
N
N
–
N
N
N
N
–
N
N
N
N
Bare steel category
10 – Austenitic 304L Stainless
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N = None; S = Slight (<15% of area); M = Moderate (15-30% of area); P = Pronounced (>30% of area)
APPENDIX 20. Extent of white residue and observations after 4 weeks.
76
APPENDIX 21
Steel ID
Lid
(Vapor Area)
Cup
Interface Area
Fuel Area
1 – EG Zinc-Nickel (with Cr+6)
N
N
N
N
–
N
N
N
N
–
N
S
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
S
N
N
–
N
S
N
N
–
N
S
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
6 – HD Terne
N
N
N
N
–
N
N
N
N
–
N
N
N
N
7 – HD Tin-Zinc
N
N
N
N
–
N
N
N
N
–
N
N
N
N
8 – HD Aluminized
N
N
N
N
–
N
N
N
N
–
N
N
N
N
9 – Ferritic 436LStainless
N
N
N
N
–
N
N
N
N
–
N
N
N
N
Bare steel category
N
N
N
N
–
N
N
N
N
–
N
N
N
N
APPENDIX 21.
Vapor area
Extent of white residue and observations after 8 weeks.
77
APPENDIX 22
Steel ID
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
+6
N
N
N
N
–
N
S
N
N
–
N
S
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
6 – HD Terne
N
N
N
N
–
N
N
N
N
–
N
N
N
N
7 – HD Tin-Zinc
N
N
N
N
–
N
N
N
N
–
N
N
N
N
8 – HD Aluminized
N
N
N
N
–
N
N
N
N
–
N
N
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
Bare steel category
Slight darkening
N
N
N
Slight darkening
–
N
N
N
Slight darkening
–
N
N
N
78
APPENDIX 23
Steel ID
+6
–
–
–
–
–
–
–
–
5 – Austenitic 304L Stainless Neukote)
–
–
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
N
S
S
N
N
N
N
N
N
N
N
N
M
M
P
M
M
M
P
M
M
P
P
P
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
M
M
Slight darkening
Slight darkening
Slight darkening
79
APPENDIX 24
Steel ID
+6
–
–
–
–
–
–
–
–
–
–
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
M
P
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
S
S
N
S
S
N
N
N
N
N
N
N
M
M
N
N
N
N
N
N
N
N
N
P
P
P
P
M
M
P
M
M
P
P
P
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
M
P
P
Slight darkening
Slight darkening
Slight darkening
N
N (1 red point)
N
N
N
N
N
N
N
N
N
N
N
N
N
80
APPENDIX 25
Steel ID
–
–
–
–
–
–
–
–
–
–
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
S
S
N
S
N
S
S
S
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
M
M
P
N
N
N
N
N
N
N
N
N
N
N
N
N
N
P
N
S
S
P
M
M
N
N
N
N
N
N
S
M
M
N
N
N
N
N
N
N
N
N
P
P
P
M
M
M
P
P
P
P
P
P
S
S
S
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
M
P
P
Slight darkening
Slight darkening
Slight darkening
N
N (1 red point)
N
N
N
N
N
N
N
N
N
N
N
N
S
81
APPENDIX 26
Steel ID
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
N
N
N
N
N
N
N
N
N
N
N
S
N
S
S
N
N
N
N
N
N
S
S
N
S
S
S
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
M
P
P
N
N
N
N
N
N
N
N
N
N
N
P
S
S
S
P
M
M
N
N
N
N
N
N
S
M
M
N
N
N
N
N
N
N
N
N
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
N
N
N
N
N
N
N
N (1 red
point)
–
–
–
–
–
–
–
–
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
N = None; S = Slight (<15% of area);
Slight darkening
N
N
P
Slight darkening
N
N
P
Slight darkening
N
N
P
M = Moderate (15-30% of area); P = Pronounced (>30% of area)
82
APPENDIX 27
Steel ID
+6
–
–
–
–
–
–
–
–
–
–
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
S
S
N
S
S
S
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
M
P
P
N
N
N
N
N
N
N
N
N
N
N
P
S
S
S
P
M
M
N
N
N
N
N
N
S
P
P
S
S
S
N
N
N
N
N
N
P
P
P
P
P
P
P
P
P
P
P
P
S
S
S
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
P
P
P
Slight darkening
Slight darkening
Slight darkening
N
N (1 red
point)
83
APPENDIX 28
Steel ID
+6
–
–
Lid
(Vapor
Area)
N
N (1 red
point)
Vapor area
Cup
Interface Area
Fuel Area
N
S
S
N
N
N
N
N
N
N
N
S
N
N
–
N
S
N
N
–
N
N
N
N
N
S
N
N
–
N
S
N
N
–
N
S
N
N
N
N
N
N
–
N
N
N
N
–
N
N
N
N
S
S
M
N
–
S
S
P
N
–
S
S
P
P
6 – HD Terne
S
S
P
S
–
S
P
P
S
–
S
P
P
S
7 – HD Tin-Zinc
P
S
P
S
–
M
S
P
S
–
M
S
P
S
8 – HD Aluminized
N
N
P
N
–
N
N
P
N
–
N
N
P
N
N
N
P
N
–
N
N
P
N
–
N
N
P
N
Bare steel category
Slight darkening
N
N
P
Slight darkening
–
N
N
P
Slight darkening
–
N
N
P
84
APPENDIX 29
Steel ID
+6
–
–
–
–
–
–
–
–
–
–
ost-painted steel category
6 – HD Terne
–
–
7 – HD Tin-Zinc
–
–
8 – HD Aluminized
–
–
–
–
Bare steel category
–
–
Lid
(Vapor Area)
Vapor area
Cup
Interface Area
Fuel Area
N
N
N
N
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
N
N
N
S
S
S
S
S
S
N
N
N
S
S
S
N
N
N
N
N
N
N
N
N
P
P
P
N
N
N
N
N
N
N
N
N
N
N
P
S
S
M
P
M
M
N
N
N
N
N
N
S
P
P
S
S
S
N
N
N
N
N
N
P
P
P
P
P
P
P
P
P
P
P
P
S
P
P
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
P
P
P
Slight darkening
Slight darkening
Slight darkening
N
N (1 red
point)
85
ID
Prepaint
Postpaint
Bare
APPENDIX 30
Exposure time, weeks
INITIAL
4
8
12
16
20
24
28
32
36
39
1-1 EG Zn-Ni
1-2 +Cr6
1-3
2-1 EG Zn-Ni
2-2 -Cr6
2-3
3-1 HDGA
3-2 -Cr6
3-3
4-1 HDAℓ
4-2 +Cr6
4-3
5-1 Stainless
5-2
5-3
58.7196
59.5354
59.1027
61.108
61.2032
60.2463
50.1409
50.8337
50.6874
56.1806
56.2672
56.1086
69.8092
69.7561
69.4543
58.7273
59.5435
59.1068
61.1135
61.2064
60.2552
50.1062
50.8008
50.6536
56.185
56.2745
56.1078
69.8256
69.7669
69.4563
58.7222
59.5401
59.1045
61.1103
61.2056
60.251
50.0978
50.794
50.6453
56.179
56.2671
56.1022
69.8222
69.7632
69.4569
58.72
59.5362
59.103
61.1095
61.2043
60.2481
50.0946
50.7936
50.6413
56.1755
56.2655
56.1008
69.8204
69.7628
69.4569
58.7178
59.5349
59.1008
61.1081
61.2025
60.2463
50.0905
50.7891
50.6401
56.174
56.2632
56.0999
69.82
69.7625
69.4555
58.7182
59.5354
59.1025
61.1095
61.2036
60.2479
50.091
50.7915
50.6397
56.1765
56.2639
56.1011
69.8187
69.7617
69.4555
58.7173
59.5346
59.1023
61.1076
61.2033
60.247
50.0919
50.7891
50.6376
56.1765
56.2638
56.1012
69.8193
69.7621
69.4566
58.7169
59.5339
59.1016
61.1073
61.2027
60.2461
50.0866
50.7876
50.6377
56.1762
56.2627
56.0993
69.8181
69.7611
69.4561
58.7182
59.5362
59.1033
61.1094
61.2031
60.246
50.0875
50.7877
50.639
56.1764
56.2652
56.1016
69.8186
69.7618
69.4567
58.7172
59.534
59.1012
61.1074
61.2025
60.2461
50.0858
50.7859
50.6344
56.1766
56.2636
56.1004
69.8194
69.7608
69.4563
58.7143
59.5312
59.0974
61.1033
61.1976
60.2422
50.0802
50.7798
50.6291
56.1725
56.2588
56.0961
69.8172
69.7608
69.4563
6-1 HD Terne
6-2
6-3
7-1 HDSn-Zn
7-2
7-3
8-1 HDAℓ
8-2
8-2
9-1 Fe Stain
9-2
9-3
10-1 304L Stain
10-2
10-3
51.1515
51.1739
51.1658
51.3344
51.3981
51.334
54.6739
54.7048
54.591
50.8958
50.8646
50.745
69.0016
69.0689
69.1909
51.1531
51.1704
51.1641
51.3329
51.4003
51.3361
54.6734
54.7061
54.5897
50.8946
50.8674
50.7452
69.0002
69.0727
69.1884
51.149
51.1696
51.1632
51.3327
51.398
51.3332
54.6727
54.7038
54.5831
50.8931
50.8654
50.7457
68.9998
69.0714
69.1892
51.147
51.1686
51.1626
51.333
51.398
51.3339
54.6731
54.703
54.5833
50.892
50.8656
50.7454
68.9983
69.0704
69.1881
51.1466
51.1672
51.1622
51.3314
51.3978
51.3317
54.6719
54.7038
54.5823
50.8955
50.8651
50.7459
68.9991
69.0707
69.1893
51.1454
51.1674
51.1608
51.3309
51.3973
51.3322
54.6716
54.7034
54.5823
50.893
50.8661
50.744
68.9996
69.0697
69.1889
51.1429
51.1682
51.1601
51.3307
51.3971
51.3316
54.6728
54.7039
54.5821
50.8959
50.8653
50.7451
68.9995
69.0705
69.1892
51.1363
51.1655
51.16
51.3308
51.3965
51.331
54.6721
54.7037
54.5828
50.8949
50.8662
50.7452
69.0002
69.0698
69.1892
51.1349
51.1625
51.1595
51.3302
51.3959
51.3309
54.6726
54.7038
54.5828
50.8944
50.8645
50.7447
69.0006
69.0704
69.189
51.1318
51.1601
51.157
51.329
51.3949
51.3313
54.6728
54.7038
54.5824
50.8953
50.8645
50.7458
69.0018
69.0709
69.1906
51.1299
51.1572
51.1552
51.3294
51.3946
51.3303
54.6732
54.7047
54.5829
50.8956
50.8663
50.7481
69.0003
69.0702
69.1894
APPENDIX 30. Actual weights of fuel test cups after fuel exposures from zero (initial) to 39 weeks.
86
APPENDIX 31
Pre-paint
Postpaint
Bare
ID
1-1 EG Zn-Ni
1-2 +Cr6
1-3
2-1 EG Zn-Ni
2-2 -Cr6
2-3
3-1 HDGA
3-2 -Cr6
3-3
4-1 HDAℓ
4-2 +Cr6
4-3
5-1 Stainless
5-2
5-3
4
-0.0077
-0.0081
-0.0041
-0.0055
-0.0032
-0.0089
0.0347
0.0329
0.0338
-0.0044
-0.0073
0.0008
-0.0164
-0.0108
-0.0020
8
-0.0026
-0.0047
-0.0018
-0.0023
-0.0024
-0.0047
0.0431
0.0397
0.0421
0.0016
0.0001
0.0064
-0.0130
-0.0071
-0.0026
12
-0.0004
-0.0008
-0.0003
-0.0015
-0.0011
-0.0018
0.0463
0.0401
0.0461
0.0051
0.0017
0.0078
-0.0112
-0.0067
-0.0026
16
0.0018
0.0005
0.0019
-0.0001
0.0007
0.0000
0.0504
0.0446
0.0473
0.0066
0.0040
0.0087
-0.0108
-0.0064
-0.0012
20
0.0014
0.0000
0.0002
-0.0015
-0.0004
-0.0016
0.0499
0.0422
0.0477
0.0041
0.0033
0.0075
-0.0095
-0.0056
-0.0012
24
0.0023
0.0008
0.0004
0.0004
-0.0001
-0.0007
0.0490
0.0446
0.0498
0.0041
0.0034
0.0074
-0.0101
-0.0060
-0.0023
28
0.0027
0.0015
0.0011
0.0007
0.0005
0.0002
0.0543
0.0461
0.0497
0.0044
0.0045
0.0093
-0.0089
-0.0050
-0.0018
32
0.0014
-0.0008
-0.0006
-0.0014
0.0001
0.0003
0.0534
0.0460
0.0484
0.0042
0.0020
0.0070
-0.0094
-0.0057
-0.0024
36
0.0024
0.0014
0.0015
0.0006
0.0007
0.0002
0.0551
0.0478
0.0530
0.0040
0.0036
0.0082
-0.0102
-0.0047
-0.0020
39
0.0053
0.0042
0.0053
0.0047
0.0056
0.0041
0.0607
0.0539
0.0583
0.0081
0.0084
0.0125
-0.0080
-0.0047
-0.0020
6-1 HD Terne
6-2
6-3
7-1 HDSn-Zn
7-2
7-3
8-1 HDAℓ
8-2
8-2
9-1 Fe Stain
9-2
9-3
10-1 304L Stain
10-2
10-3
-0.0016
0.0035
0.0017
0.0015
-0.0022
-0.0021
0.0005
-0.0013
0.0013
0.0012
-0.0028
-0.0002
0.0014
-0.0038
0.0025
0.0025
0.0043
0.0026
0.0017
0.0001
0.0008
0.0012
0.0010
0.0079
0.0027
-0.0008
-0.0007
0.0018
-0.0025
0.0017
0.0045
0.0053
0.0032
0.0014
0.0001
0.0001
0.0008
0.0018
0.0077
0.0038
-0.0010
-0.0004
0.0033
-0.0015
0.0028
0.0049
0.0067
0.0036
0.0030
0.0003
0.0023
0.0020
0.0010
0.0087
0.0003
-0.0005
-0.0009
0.0025
-0.0018
0.0016
0.0061
0.0065
0.0050
0.0035
0.0008
0.0018
0.0023
0.0014
0.0087
0.0028
-0.0015
0.0010
0.0020
-0.0008
0.0020
0.0086
0.0057
0.0057
0.0037
0.0010
0.0024
0.0011
0.0009
0.0089
-0.0001
-0.0007
-0.0001
0.0021
-0.0016
0.0017
0.0152
0.0084
0.0058
0.0036
0.0016
0.0030
0.0018
0.0011
0.0082
0.0009
-0.0016
-0.0002
0.0014
-0.0009
0.0017
0.0166
0.0114
0.0063
0.0042
0.0022
0.0031
0.0013
0.0010
0.0082
0.0014
0.0001
0.0003
0.0010
-0.0015
0.0019
0.0197
0.0138
0.0088
0.0054
0.0032
0.0027
0.0011
0.0010
0.0086
0.0005
0.0001
-0.0008
-0.0002
-0.0020
0.0003
0.0216
0.0167
0.0106
0.0050
0.0035
0.0037
0.0007
0.0001
0.0081
0.0002
-0.0017
-0.0031
0.0013
-0.0013
0.0015
APPENDIX 31. Changes in weight of fuel test cups after fuel exposures from 4 to 39 weeks (positive = weight loss).
87
APPENDIX 32
ID
Prepaint
Postpaint
Bare
1-1 EG Zn-Ni
1-2 +Cr6
1-3
2-1 EG Zn-Ni
2-2 -Cr6
2-3
3-1 HDGA
3-2 -Cr6
3-3
4-1 HDAℓ
4-2 +Cr6
4-3
5-1 Stainless
5-2
5-3
6-1 HD Terne
6-2
6-3
7-1 HDSn-Zn
7-2
7-3
8-1 HDAℓ
8-2
8-3
9-1 Fe Stain
9-2
9-3
10-1 304L Stain
10-2
10-3
INITIAL
33.5038
33.5193
33.4456
34.4235
34.3345
34.1355
28.531
29.1547
29.2427
31.793
31.7794
31.7456
39.4244
39.4167
39.3869
4
33.5035
33.5207
33.4467
34.4206
34.3342
34.1382
28.5086
29.1321
29.2217
31.7817
31.7693
31.7329
39.4262
39.4196
39.388
8
12
16
20
24
28
32
36
39
33.5031
33.5188
33.4453
34.4132
34.3283
34.1312
28.5038
29.1265
29.2154
31.7768
31.7625
31.7281
39.4258
39.4182
39.388
33.5019
33.518
33.444
34.4127
34.3267
34.13
28.5016
29.123
29.2133
31.7761
31.7618
31.7274
39.429
39.4177
39.3871
33.5006
33.516
33.4426
34.4111
34.3251
34.1276
28.4986
29.1208
29.2107
31.7754
31.7605
31.7244
39.425
39.4176
39.3873
33.5015
33.5173
33.4438
34.4116
34.3255
34.1284
28.4989
29.121
29.2109
31.7744
31.7607
31.7247
39.4248
39.4172
39.3872
33.5013
33.5172
33.443
34.4115
34.3259
34.1278
28.498
29.1204
29.211
31.7746
31.7616
31.7255
39.4251
39.4177
39.3879
33.5008
33.5167
33.4422
34.4105
34.3251
34.1273
28.4964
29.1188
29.2074
31.7732
31.7603
31.7236
39.4243
39.4171
39.3872
33.5015
33.5176
33.4431
34.4117
34.3258
34.1285
28.499
29.1219
29.2097
31.776
31.7622
31.7245
39.4246
39.4169
39.3872
33.5009
33.5168
33.4428
34.4113
34.3263
34.1283
28.4974
29.1194
29.2072
31.7742
31.7614
31.725
39.4255
39.418
39.3869
33.4993
33.5149
33.4413
34.4089
34.3234
34.1257
28.4939
29.1163
29.2038
31.7728
31.7592
31.7225
39.4241
39.4166
39.3869
28.7961
28.7135
28.8087
28.9326
29.0179
28.9318
30.8173
30.7306
30.7838
28.5948
28.6853
28.6726
39.0796
38.9533
39.0745
28.7958
28.7125
28.8081
28.9327
29.0174
28.9318
30.8178
30.7313
30.7848
28.5961
28.6863
28.674
39.0784
38.952
39.0738
28.7993
28.7988
28.7983
28.7976
28.7972
28.7973
28.7979
28.7967
28.7972
28.7165
28.7164
28.7159
28.7153
28.7149
28.7146
28.7153
28.7139
28.7138
28.8122
28.8128
28.8124
28.8116
28.8106
28.8105
28.8093
28.8096
28.8088
28.9321
28.9323
28.9322
28.9323
28.9318
28.9325
28.9323
28.9325
28.9325
29.0172
29.018
29.0177
29.0129
29.0171
29.0173
29.0172
29.0174
29.0173
28.9316
28.9323
28.9318
28.9315
28.9314
28.9309
28.9308
28.9314
28.9312
30.8197
30.8192
30.8183
30.8191
30.8177
30.8173
30.8178
30.8176
30.8172
30.7312
30.7317
30.7315
30.7309
30.7308
30.7308
30.7312
30.7309
30.7308
30.7848
30.7861
30.7849
30.7838
30.7846
30.7841
30.7845
30.7842
30.7845
28.5956
28.5962
28.5958
28.5953
28.5955
28.5953
28.5956
28.5956
28.5955
28.6851
28.6864
28.6865
28.6868
28.6857
28.6856
28.6865
28.6867
28.6855
28.6737
28.6743
28.6741
28.6748
28.6736
28.6738
28.6742
28.674
28.6737
39.079
39.0787
39.079
39.0782
39.0782
39.0783
39.0781
39.0784
39.0785
38.9524
38.953
38.9524
38.9525
38.9523
38.952
38.9527
38.9521
38.9522
39.0745
39.0739
39.074
39.0727
39.0738
39.0737
39.0743
39.0735
39.0738
APPENDIX 32. Actual weights of fuel test lids after fuel exposures from zero (initial) to 39 weeks.
88
APPENDIX 33
Pre-paint
Postpaint
Bare
ID
1-1 EG Zn-Ni
1-2 +Cr6
1-3
2-1 EG Zn-Ni
2-2 -Cr6
2-3
3-1 HDGA
3-2 -Cr6
3-3
4-1 HDAℓ
4-2 +Cr6
4-3
5-1 Stainless
5-2
5-3
4
0.0003
-0.0014
-0.0011
0.0029
0.0003
-0.0027
0.0224
0.0226
0.0210
0.0113
0.0101
0.0127
-0.0018
-0.0029
-0.0011
8
0.0007
0.0005
0.0003
0.0103
0.0062
0.0043
0.0272
0.0282
0.0273
0.0162
0.0169
0.0175
-0.0014
-0.0015
-0.0011
12
0.0019
0.0013
0.0016
0.0108
0.0078
0.0055
0.0294
0.0317
0.0294
0.0169
0.0176
0.0182
-0.0046
-0.0010
-0.0002
16
0.0032
0.0033
0.0030
0.0124
0.0094
0.0079
0.0324
0.0339
0.0320
0.0176
0.0189
0.0212
-0.0006
-0.0009
-0.0004
20
0.0023
0.0020
0.0018
0.0119
0.0090
0.0071
0.0321
0.0337
0.0318
0.0186
0.0187
0.0209
-0.0004
-0.0005
-0.0003
24
0.0025
0.0021
0.0026
0.0120
0.0086
0.0077
0.0330
0.0343
0.0317
0.0184
0.0178
0.0201
-0.0007
-0.0010
-0.0010
28
0.0030
0.0026
0.0034
0.0130
0.0094
0.0082
0.0346
0.0359
0.0353
0.0198
0.0191
0.0220
0.0001
-0.0004
-0.0003
32
0.0023
0.0017
0.0025
0.0118
0.0087
0.0070
0.0320
0.0328
0.0330
0.0170
0.0172
0.0211
-0.0002
-0.0002
-0.0003
36
0.0029
0.0025
0.0028
0.0122
0.0082
0.0072
0.0336
0.0353
0.0355
0.0188
0.0180
0.0206
-0.0011
-0.0013
0.0000
39
0.0045
0.0044
0.0043
0.0146
0.0111
0.0098
0.0371
0.0384
0.0389
0.0202
0.0202
0.0231
0.0003
0.0001
0.0000
6-1 HD Terne
0.0005
0.0010
0.0017
0.0021
0.0020
0.0014
0.0026
0.0021
0.0032
6-2
0.0001
0.0006
0.0012
0.0016
0.0019
0.0012
0.0026
0.0027
0.0030
6-3
-0.0006
-0.0002
0.0006
0.0016
0.0017
0.0029
0.0026
0.0034
0.0035
7-1 HDSn-Zn
-0.0002
-0.0001
-0.0002
0.0003
-0.0004
-0.0002
-0.0004
-0.0004
-0.0005
7-2
-0.0008
-0.0005
0.0043
0.0001
-0.0001
0.0000
-0.0002
-0.0001
-0.0007
7-3
-0.0007
-0.0002
0.0001
0.0002
0.0007
0.0008
0.0002
0.0004
-0.0002
8-1 HDAℓ
0.0005
0.0014
0.0006
0.0020
0.0024
0.0019
0.0021
0.0025
0.0024
8-2
-0.0005
-0.0003
0.0003
0.0004
0.0004
0.0000
0.0003
0.0004
0.0006
8-3
-0.0013
-0.0001
0.0010
0.0002
0.0007
0.0003
0.0006
0.0003
0.0010
9-1 Fe Stain
-0.0006
-0.0002
0.0003
0.0001
0.0003
0.0000
0.0000
0.0001
0.0008
9-2
-0.0013
-0.0014
-0.0017
-0.0006
-0.0005
-0.0014
-0.0016
-0.0004
-0.0002
9-3
-0.0006
-0.0004
-0.0011
0.0001
-0.0001
-0.0005
-0.0003
0.0000
0.0011
10-1 304L Stain
0.0003
0.0000
0.0008
0.0008
0.0007
0.0009
0.0006
0.0005
-0.0006
10-2
-0.0006
0.0000
-0.0001
0.0001
0.0004
-0.0003
0.0003
0.0002
-0.0009
10-3
0.0006
0.0005
0.0018
0.0007
0.0008
0.0002
0.0010
0.0007
0.0000
APPENDIX 33. Changes in weight of fuel test lids after fuel exposures from 4 to 39 weeks (positive = weight loss).
0.0035
0.0040
0.0041
-0.0006
-0.0002
-0.0002
0.0019
-0.0001
0.0000
-0.0005
-0.0012
-0.0003
0.0006
0.0004
0.0007
89
The Strategic Alliance for Steel Fuel Tanks Membership (SASFT):
Steel Companies - North America
AK Steel Corporation
Allegheny Ludlum / Rodney
Dofasco Inc.
Mittal Steel Company
North American Stainless
Nucor Corporation
Severstal North America Inc.
United States Steel Corporation
Steel Companies - Europe
Arcelor
Corus
ThyssenKrupp Stahl
Steel Companies – Asia
JFE Steel
Nippon Steel Corporation
Nisshin Steel
Sumitomo Metal Industries, Ltd.
Tata Steel
Material/Equipment Suppliers - North America
Comau-Pico
Harley Davidson Engineering
The Magni Group, Inc.
Material/Equipment Suppliers - Europe
Soudronic Automotive NAFTA
Associate Members (Auto Manufacturers)
DaimlerChrysler Corporation
Ford Motor Company
General Motors Corporation
Nissan Motor Co., Ltd.
Fuel System Manufacturers - North America
Elsa LLC
Fuel Systems LLC
ITT Industries
Martinrea International
Metalsa
Spectra Premium Industries
Fuel System Manufacturers - Europe
Kautex Textron
Inergy Automotive Systems
Unipart Eberspacher
Fuel System Manufacturers - Asia
Dong Hee Industrial Co. Ltd.
Horie Metal Co., Ltd.
Unipres Corporation
Fuel System Manufacturers – South America
Aethra Componentes Automotivos
For More Information on SASFT:
Visit:
www.sasft.org
Contact: Peter Mould
Program Manager
001 810.225.8250
[email protected]
For More Information on AISI:
Visit:
www.autosteel.org
Contact: Ronald Krupitzer
Senior Director
001 248.945.4761
[email protected]
90