Welding - Intelex

Transcription

Welding - Intelex
Document No. DE0512 REV 6
Automotive Service Solutions QMS
Welding of Steel
Purpose:
This specification provides the requirements for welding steel and weld symbols on drawings
Scope: This document applies to the Automotive Service Solutions; Owatonna, MN; Kalamazoo and Warren,
MI; Cleveland, OH and Romeoville, IL facilities.
Definitions:
MPa or Mega Pascal is the metric conversion from psi. 1 MPa = 145 psi.
Weld size will include English or more recently metric. Common metric sizes will include 3.00, 5.00, 7.00, 10.00,
13.00 and 16.00 mm as conversions for 0.125, 0.188, 0.250, 0.375, 0.500 and 0.625 in.
ANSI – American National Standards Institute
AWS – American Welding Society
AISI – American Iron and Steel Institute
ASTM – American Society for Testing and Materials
PWHT – Post-Weld Heat Treat
PJP – Partial Joint Penetration
CJP – Complete Joint Penetration
1.0
Documents, Forms and Equipment
The standards listed below shall be considered a part of this specification where applicable. In the event of
conflict, this document shall take precedence unless otherwise indicated and specified.
AWS D1.1-96 – Structural Welding Code – Steel
AWS A2.4-98 – Standard Symbols for Welding, Brazing, and NDT Examination
AWS A3.0-2010 – Standard Welding Terms and Definitions
Weld Standards Reference
Process Specification for Welder Qualification – PD0089
2.0 Specifications
2.1 ANSI/AWS Standards
All weld symbols on engineering drawings shall be specified and interpreted according to AWS A2.4-98 or
newer editions, except where noted in this specification. See Appendix A – Weld Callout & Symbol
Interpretations.
Drawings that do not conform to this standard may be referred to Manufacturing or Design Engineering for
clarification or update.
2.2 Material Selection
The following categories are general guidelines for the weldability of various US grades of steel that are
commonly used at these Bosch facilities. Specific questions should be directed to the Metallurgical Department.
2.2.1 Easily Weldable
AISI 1008 through 1030 low carbon steels
ASTM A36 structural steels
ASTM A500, A501, A512, A513, and A519 steel tubes
2.2.2 Weldable – May require pre-heat and post-heat as specified in routing/drawing.
AISI 1031 through 1050 medium carbon steels
AISI 4130, 4140, 4142, 4350, 6150 and 8620 alloy steels
PWHT of ASTM A514, A517, A709 grades 100 and 100W and A710 steels are not
recommended.
2.2.3 Not Easily Weldable
AISI 1050 and higher carbon steels
AISI 1117, 1141, 1144 and 4145 alloy steels
Fatigue-Proof and Stress-Proof steels
All tool steels.
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2.2.4 Not Weldable
AISI 1215 and 4150 alloy steels
All “leaded” steels
2.3 Impact Testing
When required, impact test shall be specified on the engineering drawing. The impact tests, requirements, and
procedure shall be in conformance with the provisions of AWS D1.1, Annex III or as specified in the contract
documents.
3.0 General Weld Requirements
All welding shall be performed by qualified welders only.
3.1 Qualified Welders
All Bosch welders and welding operators must be qualified per Welder Performance Qualification – PD0089
prior to welding production parts. Certified welders/welding operators shall be limited to production welding that
does not exceed their level of qualifications.
All suppliers performing production welding shall demonstrate their ability to qualify welders in accordance with
an industry accepted standard.
3.2 Filler Metal
Filler metal shall have a strength level equal to or less than matching filler metal unless otherwise specified on
the engineering drawing.
Non-certified AWS filler metal shall be qualified per AWS D1.1, Section 4 prior to usage.
3.3 Cleaning
All parts shall be adequately clean and free of oil, grease, paint, rust, or other contaminants so as not to cause
weld porosity. Removal of slag produced by Flux-Core (FCAW) or Stick (SMAW) is required after welding.
All surfaces on which weld metal is to be deposited shall be smooth, uniform, and free from fins, tears, cracks,
and other discontinuities which would adversely affect the quality or strength of the weld. Surfaces adjacent to
the weld shall also be free from loose or thick scale, slag, rust, moisture, grease, and other foreign material that
could prevent proper welding
3.4 Temperature
Welding is not permitted on material that is at a temperature lower than 45 degrees F.
Pre-heat, inter-pass and post-heat temperature (PWHT) should be in accordance with the specification on
routing and/or print.
3.5 Undercut
For thickness ≤ 25.00 mm (1.000 in), undercut shall not exceed 0.75 mm (0.030 in) with the exception that 1.50
mm (0.060 in) is permitted for an accumulated length of 50.00 mm (2.000 in) in any 300.00 mm (12.000 in) of
weld.
For thickness > 25.00 mm (1.000 in), undercut shall not exceed 1.50 mm (0.060 in) for any length of weld.
3.6 Overlap
Toe angle shall not be less than 90° for any length of weld.
3.7 Incomplete Fusion
Incomplete fusion is not permissible at the surface.
For sub-surface:
1) The height or width shall not exceed 0.75 mm (0.031 in).
2) The length of incomplete fusion shall not exceed 25.00 mm (1.000 in) or 10% of the weld length.
For fillet welds, incomplete fusion at the root of the joint is permissible as long as the effective throat is held to
nominal and other discontinuities are not exceeded. The length of incomplete fusion shall not exceed 25.00 mm
(1.000 in) or 10% of the weld length.
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3.8 Incomplete Joint Penetration
For groove welds, unless specified on engineering drawing or routing:
1) Reduced joint penetration shall not exceed 10% of the nominal weld size or 1.00 mm (0.040 in).
2) The length of incomplete joint penetration shall not exceed 10% of the weld length.
 For fillet welds, refer to Section 3.7 - Incomplete Fusion. The root and legs must have complete fusion
when qualifying welding procedures, welders and welding operators.
3.9 Underfill
The minimum weld depth must be maintained to nominal.
3.10 Weld Inclusions
Inclusions are not permissible.
3.11 Lack of Tie-In
Lack of Tie-In is not acceptable.
3.12 Arc Strike
Arc strike is not acceptable.
3.13 Weld Crater
Craters are not acceptable.
3.14 Porosity
 Visible surface pores shall not exceed 1.50 mm (0.060 in) in diameter.
 Visible surface porosity is not permissible in any weld that is required to contain pressurized or unpressurized liquid or gas.
 Sum of porosity ≥ 0.75 mm (0.030 in) diameter shall not exceed 9.50 mm (0.375 in) in 25.00 mm (1.000
in) length of weld and 19.00 mm (0.750 in) in any 300.00 mm (12.000 in) length.
 The frequency shall not exceed 1 pore in 100.00 mm (4.000 in) length of weld and diameter shall not
exceed 2.35 mm (0.090 in).
3.15 Weld Cracks
Any types of cracks in the weld face, root, or cracks in the base metal adjacent to the weld are not permitted.
3.16 Weld Spatter
A small amount of weld spatter resulting from a welding operation is permissible with the following exceptions:
1) Weld spatter on the handle of any product in an area which could result in injury to the user shall be
rejected.
2) Weld spatter is not permissible on the inside surface of any punched, drilled or tapped hole.
3) When no weld spatter is acceptable on any surface(s) of a part, it shall be clearly noted on the
engineering drawing.
3.17 Wire Stubs
All wire stub ends or “whiskers” which are embedded in the weld or fused to the base metal are not acceptable
and must be removed.
3.18 Edge Burn-Off
Sharp or jagged edges resulting from welding must be broken in any area that could be hazardous to a user.
3.19 Weld Length Tolerance
Specified weld lengths are a minimum requirement. Welds may be up to 50% longer than specified unless
otherwise toleranced on the drawing.
When welding is specified for the full length of a joint, the starting and ending points of the weld shall be within
6.35 mm (0.250 in) of the ends of the joint.
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Figure 1 – Fillet Weld
3.20 Fillet Welds
Fillet weld features are defined as shown in Fig. 1.
Weld size tolerance is:
+50%, -0% for sizes of 9.50 mm (0.375 in) or less.
+25%, -0% for sizes greater than 9.50 mm (0.0375 in).
The end of a fillet weld is allowed to be tapered (undersize) provided the length of the undersize portion does
not exceed 2 times the specified weld size.
Underrun or undersized weld bead shall not exceed 1.50 mm (0.060 in) and 10% in any length of weld. (Note:
The effective throat requirement shall be held to nominal.)
The root gap shall not exceed 0.50 mm (0.020 in) plus 10% of the effective throat prior to welding for material
3.00 mm (0.125 in) and under. For material over 3.00 mm (0.125 in), the root gap shall not exceed 1.00 mm
(0.040 in) plus 30% of the effective throat up to 4.00 mm (0.156 in). Leg size shall increase by the amount of
the root opening in order to hold the effective throat to nominal.
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The separation between faying surfaces shall not exceed 1.50 mm (0.060 in).
Base Metal Thickness (T)
in
mm
T ≤ 1/4
1/4 <T ≤ 1/2
1/2 < T ≤ 3/4
3/4 < T
T ≤ 6.40
6.40 < T ≤ 12.70
12.70 < T ≤ 19.00
19.00 < T
Minimum Size of Fillet
Weld
in
mm
1/8
3/16
1/4
5/16
3.00
5.00
6.00
8.00
Table 1 – Minimum Fillet Size Guideline
When specifying fillet sizes on engineering drawing, Table 1 above should be used as reference to determine
the correct size. Also as a guideline, the minimum effective length of a fillet weld should be at least four times
the nominal size.
Figure 2 – Fillet Weld Profiles
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3.21 Fillet Weld Profiles
The minimum effective throat, measured from the face of the weld to the root of the joint, shall not be less than
70% of the specified leg size.
Concavity is permissible as shown in Fig. 2(A) only if the effective throat and overlap requirements are met.
Convexity is permissible as shown in Fig. 2(A) and (B) dimension “C”.
3.22 Groove Weld Profiles
See AWS A2.4, Section 4, for specific groove joint weld details and interpretations. For design guideline, refer
to AWS D1.1, Section 2.3 and 3.
Maximum permissible reinforcement or melt-thru shall be 3.00 mm (0.125 in) unless otherwise specify on the
engineering drawing.
For PJP groove welds, the specified root opening between parts shall not exceed +/-1.60 mm (0.062 in) for
0.375 in thick material and under.
For CJP groove welds, the specified root opening between parts shall be +1.50 mm (0.060 in), -3.00 mm (0.125
in) for 0.375 in thick material and under.
For butt groove welds, alignment of parts shall not be offset by more than 10% of the thickness of the thinner
part joined or 3.00 mm (0.125 in).
For flare-bevel groove welds, the effective weld size shall be 5/16*R (R = radius of outside surface) and 3/8*R
for flare-V groove welds, assuming the weld is filled flush to the surface.
3.23 Plug and Slot Welds
See AWS A2.4 for specific plug and slot weld details and interpretation. For design guideline, refer to AWS
D1.1, Section 2.5 and 3.10.
Depth of fill is indicated by a dimension shown inside the weld symbol. When not dimensioned, depth of fill shall
be complete. Tolerance on depth of fill is 3.00 mm (0.125 in), -0 when mechanical finishing is not indicated.
The separation between faying surfaces shall not exceed 1.50 mm (0.060 in).
Complete fusion at the bottom of the hole and around the sides, for the specified depth of fill, is required.
Welds are not permitted in quenched and tempered steels.
3.24 Weld Repair
Defective welds shall be repaired under the direction of Manufacturing Engineering. Repaired welds must meet
the original weld specification unless otherwise approved by Design Engineering. Refer to the Weld Standards
Reference for repair guidelines.
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Appendix A
Figure 1 - Weld Callout & Symbol Interpretations
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