Hard chrome - Schulte

More than a century of competence and experience
With state-of-the-art production techniques and experienced
staff, we process your workpieces of up to 40t individual weight in
the area of hard chrome plating and precision grinding. Creative
solutions and flexibility are our hallmark.
For all coating questions, we offer competent, comprehensive and
coordinated counseling for the specific task.
With competence and experience toward the future:
Joh.-Georg Lex, Tanja Lex and Stephan Giese-Lex
Overview of services
The examples of applications from industry
are wide-ranging and international:
Printing: metering rolls, impression cylinders, embossing rolls
Food: drying cylinders, cooling rolls, endless screws, housings, baking sheets
Paper converting: gel cylinders, gum application cylinders, contact pressure
rolls, calender rolls, guide rolls, idle rolls, doctor shafts
Plastics processing: mirror-finish rolls, laminating rolls, heating and cooling
rolls, nozzles, barrel extruders, handrails, pressing and drawing molds, doctor
shafts, chromed steel pressure plates and strips, heating and cooling plates
Aviation and astronautics: valve stems
Military engineering: punch calibers und impellers
Textile industry: pressure rolls, thread deflecting rods, galettes, spindles
Automobile engineering: tool molds, pressing and drawing molds
Hydraulics: cylinders, piston rods, plungers, outer bodies
Chemical industry: Gas scrubbers, worm conveyors
Mechanical and plant engineering: drawing and bending tools, valve bodies,
shafts, couplings, impellers
Structural steel engineering: working rolls and cold-working rolls and other
branches of industry
We offer these services:
industrial hard chrome plating
chrome plating to size
cylindrical grinding
mirror-finish grinding
belt grinding
polishing
dull and satin polishing
selective coating
APC coating
special work and service
supply of complete sets
Certifies:
SHEET METAL & PLATES
Sheet metal & plates
Large-format chrome steel pressed sheets and strip, heated plates
and cold plates:
We chrome large-format pressed sheets and strips for all the wellknown German suppliers. These are used for the production of
laminates and melamine-coated wood-based panels for the floor and
furniture industries. The hard chrome layer serves for wear protection
and provides a gloss finish for the product.
Our hard chrome process has also won a reputation worldwide as wear
protection for the coating of heated plates and cold plates. These are
mainly used in hydraulic presses for the manufacture of chipboard
panels but also for plastic panels (PE, PP, PVC, PVC-C). In this area, we are
also happy to carry out complete processing operations for you with all
the necessary mechanical processing steps. In general, hard chroming
of metal sheets and plates is possible up to a width of 2800 mm and a
length of 8500 mm while the maximum weight per item can be up to
10t. Please contact us separately for special dimensions.
HARD CHROME
Hard chrome
Hard chrome plating is still a forward-looking process for the
production of the highest surface qualities for low-friction, low-wear
manufacturing operations to reduce your costs . With its high surface
hardness, hard chrome plating helps increase service life by reducing
wear. It provides corrosion protection, prevents adhesion and
prolongs the service life of gloss qualities.
It also has a low coefficient of friction and improves thermal stress
stability. Its worth has likewise been demonstrated for the refurbishing
of workpieces that are damaged, worn or with dimensions smaller
than specified. We offer our customers a very wide range of productspecific processes. Some of the special electrolyte baths used in these
processes achieve a chrome hardness of up to 1100 HV 0.1.
Using a well-established processing method
with the latest sophisticated technology,
we can also offer hard-chrome coatings for
precision metering rods. Our extremely wearresistant coatings are characterized by top
quality for a wide range of application areas
such as film presses, size application and all
kinds of direct applications.
As the market leader in this area, we are in a
position to coat metering rods of VA material
9.75 mm in diameter and of a total length of
13,000 mm with a coating thickness variation
of 3 μm.
All the metals and their alloys currently used in mechanical and plant
engineering can be hard-chromed by us, e.g.
• plain carbon steels
• high-alloy hardened steel
• stainless steels and carbon steels
• cast steel
• gray cast iron
• ductile cast iron
•titanium
•copper
•brass
•bronze
• all aluminium alloys
HARD CHROME
Unilay single-layer process
Precision hard chroming
The Unilay single-layer process is suitable for use in
the standard dry area and is a cost-effective alternative
with layer thickness application up to 50 µm for an
unproblematic and long-lasting surface.
Precision hard chroming for very close tolerance zones
is suitable for a layer thickness of up to 50 µm and ISO f7
tolerance.
Multilay multi-layer process
M3 process
The Multilay multi-layer process offers increased protection
from corrosion and lower wear with a two- or three-layer
structure including the intermediate polishing of the individual
hard-chrome layers. The final result with a total layer thickness
of 50µm and more assures superior corrosion protection and is
less affected by thermal stress..
The M3 process is suitable for use in the wet area. Through
a special layer structure of 50µ and more, we obtain a high
degree of protection from corrosion. Salt spray tests as
specified in DIN 50021SS showed that the chrome layer does
not display any signs of corrosion after 120 hours. Workpieces
are always delivered to customers with an APC coating.
Oversize chrome plating
2xM3-Verfahren
Oversize chrome plating for mechanical reworking is
suitable for an added layer thickness of 2.0 mm and for worn
workpieces to attain accuracy of fit and top-quality surfaces
in the chrome layer.
Suitable for workpieces in the wet area, e.g., in a maritime and
tropical climate or in mining. Advantages: with a layer thickness of
not less than 75 µm, even better corrosion protection. Salt spray
tests as specified in DIN 50021SS showed that the chrome layer
does not display any signs of corrosion after 360 hours. Workpieces
are always delivered to customers with an APC coating.
Typical results of a mixed acid electrolyte
Property
Thermal conductivity
Magnetic susceptibility
Linear coefficient of thermal expansion
Modulus of elasticity
Tensile strength
Adhesion to steel
Value
69,069
2,6 10-6
6,6 10-6
132,4 to 156,9
98 to 390
over 1000
Unit
J/(m s k)
cm3/g
1/K
GPa
Mpa
N/mm2
ChroMo1 process
The ChroMo1 process means a newly developed hardchrome layer with a 1% molybdenum component through
the use of a specially prepared electrolyte. Advantages:
higher thermal hardness (over 400°C), considerably greater
resistance to acidic media containing chlorine, limitation of
chrome corrosion and high ductility. We offer this exclusive
process worldwide.
SERVICE & SPECIAL WORK
Flexible service
Selective coating/Spot welding technique
With the selective coating/spot welding technique which can also be carried
out on your premises, we are able in the great majority of cases to carry out
a repair of the workpiece on the spot in the installed state. Faults are rapidly
corrected by our expert personnel, including any preparatory and finishing
work which may be necessary. You can naturally make use of our services
at any time in this and other countries. Our staff have already gained
experience also in Russia, ex-Yugoslavia, Turkey and China.
Overhaul and reworking
Vollständiges Aufarbeiten sowie Umarbeiten von Werkstücken wie z.B.:
• lathe work
• reworking of journals
• replacement of damaged roll sleeves
• overhauling of complete hydraulic units and many other items on
request
• processing of precision doctor rods and more.
We supply complete sets of equipment (rolls, piston rods, doctor shafts,
complete hydraulic units, etc.).
Competent partners make sure that work which cannot be carried out
on our premises does not cause an additional problem for our customers.
This means that the responsibility for your complete order remains at a
single source.
GRINDING
Grinding technique
Attainment of the technical parameters demanded
The grinding technique is the basis for the attainment of technical
parameters.
With our comprehensive stock of machines for precision, cylindrical
grinding, belt grinding and polishing work, we can meet the most
diverse requirements for a very wide range of workpiece dimensions.
Depending on the geometry, material and execution of the workpiece,
precision results of < 0.003 mm und Rt 0.1 μm can be attained in
dimensional accuracy, true running, cylindrical form and peak-tovalley height of convex and concave curves.
Cylindrical grinding
External cylindrical grinding. Preparatory and finishing work of
chromed workpieces or straight grinding work in the external grinding
area is carried out with the following grinding techniques: precision
cylindrical grinding, mirror-finish grinding.
SATIN & POLISHING
Polishing technique
Polishing technique for prepared surfaces and defined peak-to-valley
heights. The production of defined peak-to-valley heights and other
surfaces of a visual nature and preparatory, intermediate and finishing
work for hard chrome processes are carried out with the following
polishing techniques: industrial polishing, wet and dry belt grinding,
manual polishing.
Satin polishing
ø-mm
Length grinding Length total
Weight in kg
Stone grinding between centers to
800
5.250
5.250
10.000
Stone grinding in supports
to
3.500
4.860
7.000
40.000
to
2.500
6.250
7.000
40.000
Belt grinding centerless
to
1.000
20.000
20.000
10.000
Belt grinding in supports
to
3.400
3.600
7.000
30.000
to
2.000
4.600
7.000
30.000
Greater dimensions and weights possible on request.
With our dull and satin polishing technique, we are able to obtain the
required peak-to-valley height in the basic material or in the chrome
on your workpieces of a diameter up to 2,500 x working length
9,000 x total length 10,000 mm and a max. weight of 8,000 kg
(larger dimensions and higher weights on request). Our workshop can
make the necessary jig for the processing of the workpieces.
APC COATING
APC coating= Adamant Protective Coat
adamant: Diamant {noun}, diamond of extreme hardness {f }, Adamant
{m} [imaginary stone of impenetrable hardness]
adamant {adj.}: firm, very hard, stubborn, determined, unyielding,
steadfast, unshakable, immovable [fig.]
adamant [poet.] - unusual hardness {f }
to be adamant that - to insist that
As a follow-up treatment, APC coating is an innovative process by
which the micro and macro cracks in the hard chrome layer are sealed.
This improves the sliding characteristics and corrosion resistance to an
even greater degrees.
This special process was developed in our company in the course of a
graduate thesis by our quality management engineer, continuously
improved, tested for suitability over the last few years and matched to
the process in an optimal manner. Pilot series were subjected to a
series of tests which included corrosion resistance behavior and
supplied important empirical values so that we are now able to offer
first-class results also in this area.
TOOLS
Tools
The process:
Our specialties include the hard chrome plating of tools and molds.
This process, characterized by layer thicknesses of 10 µm to 30 µm, is a
cost-effective alternative precisely in the deep-draw area and for
punching tools.
The shape of the tool is protected by this since its working surface is
provided with a thin and extremely low-wear hard-chrome layer. All
friction effects stop at the chrome layer, increasing process safety and
availability with a lower maintenance requirement and longer tool life.
These economic factors mean a considerable competitive advantage
since the process can be used again for the refurbishing of a tool.
For many years, we have also been a partner of the mold manufacturers,
especially in the SMC area. The striking feature of hard chrome here is its
avoidance of adhesion effects. The release of the finished part from the
mold is simplified, tool wear is greatly reduced and costs can be saved
through this.
TOOLS
The advantages at a glance
• high-quality surface finishes for maximum slidability
• thanks to sophisticated anode technology, different layer thicknesses
can be applied with precision dank
• the tool keeps its shape, even when rechromed a number of times
• at the low chrome plating temperature of 55 ° C, thermal distortion is
excluded
• the short process time of 1 - 6 hours means short refurbishing times
• improved flow of material in the drawing process and improved
qualities
• greatly reduced sheet-metal abrasion and very much lower reject rate
• higher press speeds and increased productivity
• lower lubricant requirement
• avoidance of adhesion effects
Capacities:
Workpieces up to 40 t, greater weights on request.
Environment, QA and certification
What quality assurance means for you:
Production reliability and sure results
Comprehensive quality tests, continuous workforce training
courses and the application of the latest measuring technology
characterize the reliability of the process. Regular internal audits
ensure consistent quality. We naturally have DIN EN ISO 9001:2008
certification.
What environmental protection means for you:
The latest technologies employed by us
protect the environment. Wastewater-free
production, tertiary safety systems at the
baths, evaporators and inliners assure
optimum safety.
Our environmental and safety
management is certificated as specified in
the internationally recognized standards of
DIN EN ISO 14001:2005 (Environment) and
BS OHSAS 18001:2007 (Industrial Safety).
Service
Flexible service
Selective coating/Spot welding technique
With the selective coating/spot welding technique which can
also be carried out on your premises, we are able in the great
majority of cases to carry out a repair of the workpiece on the
spot in the installed state.
Complete sets:
We supply complete sets of equipment (rolls, piston rods,
doctor shafts, complete hydraulic units, etc.).
Overhaul and reworking
We undertake the complete reworking of workpieces, e.g.:
Werkstücken wie z.B.:
- lathe work
- reworking of journals
- replacement of damaged roll sleeves
- overhauling of complete hydraulic units and many other
items on request
- processing of precision doctor rods and more.
At the locations of Oeventrop (individual parts, small runs and massproduced parts, long cylindrical workpieces, large-format plates and
endless belts) and Iserlohn (small and large tools – for example, for
the automotive industry -, rolls/cylinders and hydraulic parts with
and without exacting mechanical primary and secondary operations
in small to large dimensions), we respond flexibly and on time to the
wishes of our customers.
Location l
Heinrich Schulte Söhne GmbH & Co. KG
Widayweg 10
59823 Arnsberg
Tel.: +49 2937 9681-0 . Fax: +49 2937 9681-29
[email protected] . www.schulte-soehne.eu
Location ll
Echelnteichweg 39
58640 Iserlohn
Tel.: +49 2371 43479-0 . Fax: +49 2371 43479-12
[email protected] . www.schulte-soehne.eu