Higher Performance Capacity
Through the Use of Coatings
Coated rolling bearings and precision components
Contents
Coating systems and their areas of application
Coatings · Overview
1 Main function Anti-corrosion protection
and fretting corrosion
2 Main function Anti-wear protection /
friction reduction
3 Main function Current insulation
4 Main function Surfaces subjected to high
tribomechanical stresses
1 Main function – Anti-corrosion protection
and fretting corrosion
Corrotect ® coating systems:
Corrotect ® thin layer coating (zinc-iron alloy)
Corrotect ® ZI (zinc-iron alloy)
Corrotect ® ZN (zinc-nickel alloy)
Corrotect ® ZK (zinc, electroplated)
Corrotect ® ZF (zinc, lamellar coating)
2
3
3
4
5
5
6
7
8
8
9
2 Main function – Anti-wear protection / friction reduction
Durotect ® coating systems:
Durotect ® B (mixed iron oxide)
10
Durotect ® Z (zinc phosphate)
11
Durotect ® M (manganese phosphate)
12
Durotect ® CK (columnar hard chromium coating)
13
Durotect ® CK + (columnar hard chromium coating
+ anti-friction coating)
14
Durotect ® CM (microcracked hard chromium coating)
15
Durotect ® NP (nickel-phosphorus coating)
16
Durotect ® C (copper) and Durotect ® S (silver)
17
Durotect ® HA (hard anodising)
17
Durotect ® polymer-based coating systems:
Durotect ® P (polymer-based coating)
18
3 Main function – Current insulation
Insutect ® coating system:
Insutect ® A (aluminium oxide)
19
4 Main function – Surfaces subjected to high
tribomechanical stresses
Triondur ® coating systems:
Triondur ® C (metal-doped carbon coating)
20
Triondur ® C + / CX + (amorphous carbon coating)
21
Triondur ® CH (hydrogen-free amorphous carbon coating) 21
Triondur ® CN (chromium nitride)
22
Triondur ® CNN (chromium carbonitride)
22
Triondur ® TN (titanium nitride)
23
Coating systems and their areas of application
Anti-corrosion protection
Corrotect® HA (AI)
Corrotect® A*, C, F
Corrotect® N*, P, T
Durotect® ZK
Corrotect® ZI
Corrotect® ZN
Durotect® ZF
Anti-wear protection
Durotect® NP
Insutect® A
Durotect® CK
Durotect® CM
Triondur® TN
Durotect® P
Durotect® CK*
Triondur® CX+
Triondur® C, C+
Triondur® CN, CH
Insulation
Insutect® A
Durotect® B
Durotect® M
Durotect® Z
Durotect® C
Durotect® S
Durotect® P
Friction reduction
2
Coatings · Overview
Bearings and precision components from the Schaeffler
Group offer high performance capacity and a long
operating life. They provide the user with thoroughly
developed and economical solutions for the large
majority of requirements. The characteristics of the
components can be expanded by the use of suitable
coating systems, thus offering the customer advantages
in the application. The Schaeffler modular coating
concept allows a dedicated solution for the customer
with the coating as a design element.
Through the prevention of corrosion and wear, Schaeffler
coating systems contribute to the conservation of
resources, since the operating life of the components
is extended significantly. By reducing friction, the
coatings contribute to energy efficiency in the form
of reduced energy consumption.
The coating systems are applied to the surface by a wide
variety of methods. They should always be individually
matched to the mounting situation.
In many cases it is sufficient to coat only one of the
components in rolling contact or only a part thereof.
This Technical Information gives an overview of the
coatings used at Schaeffler, arranged according to
the main areas of application. The features, advantages
and benefits are given for each type of coating.
Specific examples and references are shown.
Further information:
[email protected]
1 Main function: Anti-corrosion protection – Corrotect ® coating systems
Designation
Coating system
Comment
Suffix
Main functions
Anti-corrosion Anti-wear
protection
protection
Corrotect® A*
Zinc alloy
CT001
X
–
Corrotect® N*
CT004
X
–
Corrotect® ZK
Zinc
CT010 – CT013
Zinc-iron
CT020 – CT023
Zinc-nickel
CT030 – CT033
Zinc lamellae
CT100
X
Corrotect® ZI
Corrotect® ZN
Corrotect® ZF
Friction
reduction
Additional Main area of application
function
Special feature
Automotive, belt drives, selector shafts,
bearings, bearing components,
Cr(VI)-free
Automotive, belt drives, detents,
Cr(VI)-free
Simple anti-corrosion applications
X
–
Industrial, Automotive, belt drives,
bearing components, screws
X
–
X
–
Industrial, Automotive, belt drives,
bearing components, screws
Industrial, Automotive, chassis
engineering, components, screws
3
Coatings ∙ Overview
2 Main function: Anti-wear protection and friction reduction – Durotect ® coating systems
Comment
Suffix
Durotect® B
Mixed iron oxide
CT240
X
Durotect® Z
Zinc phosphate
CT250 – CT251
X
Durotect® M
Manganese
phosphate
CT260 – CT261
X
Durotect® CK
Columnar hard
chromium coating
CT230
Durotect® CK+
Columnar hard
chromium coating
plus mixed
chromium oxide
CT231
Durotect® CM
Microcracked hard
chromium coating
CT220 – CT224
Durotect® NP
Chemical nickel
CT200 – CT205
Durotect® C
Copper
CT270
Silver
CT271
Durotect® S
Durotect® HA
Durotect® P
4
Main functions
Anti-corrosion Anti-wear Friction
protection reduction
protection
Designation
Coating
system
Hard anodising (Al)
Polymer-based
coating
CT700 – CT702
X
X
X
X
Additional
function
Main area of application
Special feature
Improved running-in
behaviour, reduced
slippage damage,
slight anti-corrosion
protection
Temporary anti-
Industrial, Automotive,
bearing components,
wind energy, full complement
roller bearings
corrosion protection,
protection against
fretting corrosion,
suitable for sliding
seats
Improved runningin behaviour, slight
anti-corrosion protection, emergency
running lubrication
Anti-corrosion
protection, slight
reduction in friction,
reduced fretting
corrosion
Industrial, Aerospace,
linear guidance systems,
bearings, bearing components
Industrial, Automotive,
Aerospace, bearing components
Industrial, Linear Technology,
Aerospace, vibratory screen
bearings, helicopter bearings,
spindle bearings
Additionally good
anti-corrosion
protection
Industrial, bearing components,
linear technology
X
Slight anticorrosion protection, slight reduction in friction
Industrial,
needle roller bearings
X
–
Industrial, drawn cups,
guide ring segments
Industrial, cages
X
X
X
Emergency running
lubrication
X
Emergency running
lubrication
X
X
Current insulation
Protection against
fretting corrosion
Reduction in friction
Industrial, Aerospace,
linear guidance systems,
bearing components, cages
Automotive, sliding sleeves
Industrial,
bearing rings
Coatings ∙ Overview
3 Main function: Current insulation – Insutect ® coating systems
Designation
Coating
system
Comment
Suffix
Insutect® A
Aluminium
oxide
Main functions
Anti-corrosion Anti-wear
protection
protection
Main area of application
Special feature
Friction
reduction
Main function
Current insulation
Industrial, rail vehicles,
electric motors,
generators
4 Main function: Surfaces subjected to high tribomechanical stresses – Triondur ® coating systems
Additional
function
Main area of application
Special feature
X
–
Automotive,
valve train components
X
X
–
X
X
Reduced slippage
damage
Automotive,
valve train components
Industrial, Automotive,
bearing components,
engine components
a-C:H
CT450 –CT479
X
X
–
Triondur® CX+
a-C:H:X
CT480 – CT509
X
X
Minimal friction in
valve train
Triondur® TN
TiN
CT415 – CT419
X
Triondur® CH
ta-C
CT520 – CT529
X
Main functions
Anti-corrosion Anti-wear
protection
protection
Designation
Coating
system
Comment
Suffix
Triondur® CN
CrxN
CT400 – CT404
CrN/CrC
CT405 – CT409
a-C:H:Me
CT420
X
Triondur® C+
Triondur® CNN
Triondur® C
Friction
reduction
–
Industrial, Automotive,
engine components,
bearing components
Automotive,
valve train components,
bearing components
Aerospace,
bearing components,
rib surfaces
Automotive
5
1
Main function: – Anti-corrosion protection
Corrotect ® thin layer coating (zinc-iron alloy)
Features
Colour: dependent on post-treatment
A*:
iridescent silver - Cr(VI)-free
N*:
silver, slightly iridescent - Cr(VI)-free
Coating structure
Zinc-iron coating with passivation A*/N*
Layer thickness
0,5 – 3 μm
or 2 – 5 μm.
A* = thick layer passivation
N* = nanoparticle-based passivation
Advantages/benefits
• Anti-corrosion protection, 48 – 360 hours against
red rust formation (depending on design type) in
accordance with salt spray test to DIN EN ISO 9227.
• Economical cathodic anti-corrosion protection.
• Thin layer coating technology allows complete
bearing coating without taking account of tolerances.
Applications
• Various bearings, bearing components and bearing
adjacent parts with requirement for increased
corrosion resistance, e. g. bearing inner rings /
outer rings / rolling elements; drawn cup needle
roller bearings and thin-walled components in large
quantities, e.g. detent sleeves.
6
1
Main function: – Anti-corrosion protection
Corrotect ® ZI (zinc-iron alloy)
Features
Colour: dependent on post-treatment
A*:
iridescent silver - Cr(VI)-free
N*:
silver, slightly iridescent - Cr(VI)-free
Coating structure
Zinc-iron coating with passivation A*/N*
Layer thickness
Dependent on requirement, 5 μm or more.
A* = thick layer passivation
N* = nanoparticle-based passivation
Advantages/benefits
• Anti-corrosion protection, 120 – 600 hours against
red rust formation (depending on design type) in
accordance with salt spray test to DIN EN ISO 9227.
• Economical cathodic anti-corrosion protection.
Applications
• Automotive and industrial components with
requirement for increased anti-corrosion protection
• Large size bearings in rolling mill sector.
7
1
Main function: – Anti-corrosion protection
Corrotect ® ZN (zinc-nickel alloy)
Features
Colour: dependent on post-treatment, preferably with
thick layer passivation A* silver, at some
points slightly iridescent yellow; Cr(VI)-free
Coating structure
Zinc-nickel coating with thick layer passivation A*.
Layer thickness
Dependent on requirement, 2 μm or more.
Advantages/benefits
• Anti-corrosion protection, 360 – 720 hours against
red rust formation (depending on design type) in
accordance with salt spray test to DIN EN ISO 9227.
• High quality cathodic anti-corrosion protection.
Applications
• Automotive and industrial components with
requirement for very high anti-corrosion protection,
such as joint and detent bushes, bearing pins,
mechanical levers, etc.
Corrotect ® ZK (zinc, electroplated)
Features
Colour: dependent on post-treatment, preferably with
thick layer passivation A* silver, at some
points slightly iridescent yellow; Cr(VI)-free
Layer thickness
Dependent on requirement, 5 μm or more.
Advantages/benefits
• Anti-corrosion protection, 24 – 360 hours against
red rust formation (depending on design type) in
accordance with salt spray test to DIN EN ISO 9227.
Applications
• Simple adjacent parts.
8
1
Main function: – Anti-corrosion protection
Corrotect ® ZF (zinc lamellar coating)
Features
Colour: silver-grey
Coating structure
Soft zinc lamellar coating,
partially cathodic, paint-type anti-corrosion protection.
Layer thickness
8 – 15 μm
Advantages/benefits
• Anti-corrosion protection, up to 720 hours against
red rust formation (salt spray test to DIN EN ISO
9227).
Applications
• Principally automotive sector:
wheel bearings, sensor and intermediate rings,
screws.
9
2
Main function – Anti-wear protection / friction reduction
Durotect ® B (mixed iron oxide)
Features
(dependent on material)
Colour: dark brown to deep black
Coating structure
Coating comprising mixed iron oxides.
Layer thickness
0,5 – 2 μm.
Advantages/benefits
• Improvement in running-in behaviour of bearings
• Favourable under low risk of slippage.
Applications
• Rolling elements and rings for bearings in wind
turbines and railway drive bearings
• Full complement cylindrical roller bearings
• Ball bearings under poor lubrication conditions.
10
2
Main function – Anti-wear protection / friction reduction
Durotect ® Z (zinc phosphate)
Features
Colour: grey/black
Coating structure
Zinc phosphate
Layer thickness
1 – 10 μm
Advantages/benefits
• Anti-corrosion protection in oiled condition, up to
48 hours against red rust formation (salt spray test to
DIN EN ISO 9227).
• Prevention of fretting corrosion in the bearing seat
• Friction reduction promotes displacement effect.
Applications
• Tapered roller bearings in rail vehicles
• Large bearings – paper industry
• Expander roller eccentric bearings
• Rolling bearing cages and drawn cups.
11
2
Main function – Anti-wear protection / friction reduction
Durotect ® M (manganese phosphate)
Features
Colour: matt dark grey
Coating structure
Manganese phosphate
Layer thickness
1 – 10 μm
Advantages/benefits
• Improvement in sliding and running-in behaviour.
Applications
• Roller coating in bearings in mixer gearboxes
• Sheet steel cages
• Adapter and withdrawal sleeves
• Inner ring bores in crankshaft bearings
• Primary layer for anti-friction paints.
12
2
Main function – Anti-wear protection / friction reduction
Durotect ® CK (columnar hard chromium coating)
Features
Colour: matt grey
Coating structure
Chromium coating with columnar surface surface.
Layer thickness
Functional surfaces:
Secondary surfaces:
1 – 3 μm
1 – 6 μm.
Hardness: approx. 1 000 HV.
Advantages/benefits
• High wear resistance (high hardness) especially at
the axial contact running points or on fit surfaces
where fretting corrosion is expected
• Effective anti-wear protection under mixed friction
for small ball or roller bearings
• Low friction factors under mixed friction due to
smoothing of the pearly structure after the running-in
process
• Reduced friction factors allow unconstrained
displacements in non-locating bearings
• Corrosion resistance approx. 5 times higher
compared with rolling bearing steel
(salt spray test to DIN EN ISO 9227).
Applications
• Raceways in high precision bearings
• Outside diameter of spindle bearings
• Complete coating of spherical roller bearings
(rings, rolling elements) running in corrosive
environments
• Bore of vibratory screen bearings against fretting
corrosion / vibratory wear
• Ball bearing rings for swash plates in helicopters
• Linear components.
13
2
Main function – Anti-wear protection / friction reduction
Durotect ® CK + (columnar hard chromium coating + + anti-friction coating)
Features
Colour: black
Coating structure
Smooth upper layer comprising mixed chromium oxide
on columnar chromium layer.
Layer thickness
As Durotect ® CK plus 0,5 – 3 μm
Hardness: approx. 1 000 HV; the covering layer is soft
and malleable under load.
Advantages/benefits
• Improved running-in behaviour
• Improved friction and wear behaviour under lubricant
starvation (the depressions between the chromium
pearls act as a “lubricant reservoir“ for the chromium
oxide).
• Extension of maintenance intervals in rail transport
When the bearings are used in aggressive atmospheres
and at high temperatures, the thick layer acts in a
supporting role to the lubricant compared with pure
thin layer chromium plating and increases the
corrosion resistance.
Due to mechanical load, the soft thick layer is
compacted into the pearly structure. The resulting grey
functional layer reveals the base layer Durotect ® CK.
Applications
• Traction motor bearings in rail vehicles
• Back-up rollers for multi-roll cold rolling mills
• Linear components.
14
2
Main function – Anti-wear protection / friction reduction
Durotect ® CM (microcracked hard chromium coating)
Features
Colour: lustrous silver, replicates subsurface structure
Coating structure
Smooth, microcracked hard chromium coating.
Layer thicknesses
0,1 – 500 μm, depending on the application
(suitable for mechanical processing).
Hardness: approx. 850 – 1 100 HV.
Advantages/benefits
• Improved friction and wear behaviour under lubricant
starvation
• Increased life due to hard surfaces as anti-wear
protection
• Good anti-corrosion protection and high resistance to
many chemicals with coating thicknesses over 30 μm
• Temperature resistance up to +300 °C
• Protection against tribocorrosion
• Low friction coefficient / good sliding characteristics
• Anti-adhesive characteristics.
Applications
• Spherical plain bearing applications
• Automotive and industrial products subjected to wear
loads.
15
2
Main function – Anti-wear protection / friction reduction
Durotect ® NP (nickel-phosphorus coating)
Features
Colour: metallic silver, slight yellow tinge
Coating structure
Chemically deposited nickel coating,
with 8 – 15 % phosphorus in the alloy.
Layer thickness
Dependent on requirement
For anti-corrosion protection
8 – 15 μm,
25 – 300 μm.
Hardness
500 – 600 HV
(increasable by heat treatment to 750 – 1 000 HV).
Advantages/benefits
• Coating true to contours of component, in some
cases also in depressions
• Combined characteristics of anti-wear protection
and anti-corrosion protection allow a wide range of
applications
• High coating thicknesses give very good anti-corrosion
protection characteristics
• Suitable for mechanical processing in certain cases.
Applications
• Guide rings, spherical roller bearings
• Spherical plain bearings
• Housings for the food industry
• Usage in fresh water/salt water applications.
Special features
Durotect ® NP can be dispersed by means of PTFE or
hard material particles (diamond, SiC) in order to
optimise the sliding characteristics or improve the wear
resistance.
16
2
Main function – Anti-wear protection / friction reduction
Durotect ® C (copper) and Durotect ® S (silver)
Features
Colour: copper-coloured or silver-coloured
Coating structure
Durotect ® C copper
Durotect ® S silver with copper intermediate layer.
Layer thickness
Dependent on requirement, 2 – 50 μm.
Advantages/benefits
• Improvement in emergency running behaviour
Applications
• Sheet steel cages in two-stroke and four-stroke engines
• Cages for aerospace applications.
• Large size bearing cages
Durotect ® HA (hard anodising)
Features
Colour: silver to mouse grey
Coating structure
Durotect ® HA, aluminium oxide layer.
Layer thickness
Dependent on requirement, 2 – 25 μm.
Advantages/benefits
• Increase in wear resistance of aluminium
• Current insulation.
Applications
• Aluminium sliding sleeves in clutch bearings
• Aluminium cages for aerospace applications.
17
2
Main function – Anti-wear protection / friction reduction
Durotect ® P (polymer-based coating)
Features
Colour: dependent on coating system
Coating structure
Polymer-based coating
Layer thickness
10 – 20 μm.
Advantages/benefits
• Improvement in sliding capacity on the bearing outer
ring, reduction in the friction factor to < 0,1 under
axial displacement of bearing rings.
Applications
• Quadropol mills for cement production
(outer ring outside surface of spherical roller bearings)
• Suction box rolls and thermo rolls in paper machinery
(outer ring outside surface of spherical roller bearings)
• Main rotor bearing arrangements – wind power.
18
3
Main function – Current insulation
Insutect ® A (aluminium oxide)
Features
Colour: light grey to matt beige
Coating structure
Ceramic coating comprising aluminium oxide Al 2 O 3 with
sealant.
Layer thickness
100 – 200 μm, higher upon customer request.
Advantages/benefits
• Current insulation according to coating type –
resistance to current puncture up to 3 000 V.
• Anti-corrosion protection.
Applications
• Bearings in threephase motors
• Traction motor bearings
• Wheelset bearing arrangements
• Bearings in generators.
Details: see TPI 206, Current-Insulating Bearings.
19
4
Main function – Surfaces subjected to high
tribomechanical stresses
Triondur ® C (metal-doped carbon coating)
Features: see TPI 115
Colour: matt greyish black
Coating structure
Hard amorphous hydrocarbon coating of lamellar
type structure with content of tungsten and tungsten
carbides.
The surface structure is smooth.
Layer thickness
0,5 – 4 μm.
Friction reduction in DLC/steel compared with
steel/steel (dry in each case) 80 percent.
Hardness: 1 100 – 1 500 HV
Advantages/benefits
• Effective anti-wear protection under mixed friction
• Higher wear resistance due to high hardness
• Favourable under adhesive wear due to the low
friction factor
• Highly suitable under slippage risk.
Applications
• Barrel rollers in spherical roller bearings
for paper calenders
• Barrel rollers in axial spherical roller bearings
for hydraulic motors
• Track rollers with coated outside diameter
for the printing industry.
20
4
Main function – Surfaces subjected to high
tribomechanical stresses
Triondur ® C + / CX + (amorphous carbon coating)
Features: see TPI 115
Colour: black
Coating structure
Hard lamellar type amorphous non-metallic hydrocarbon coating.
Triondur ® CX + is doped with non-metals. The surface structure is
smooth.
Layer thickness
2 – 4 μm. Friction reduction in DLC/steel compared with steel/steel
(dry in each case) 85 percent.
Hardness: > 2 000 HV.
Advantages/benefits
• Very high anti-wear protection under mixed friction
• Higher wear resistance due to high hardness
• Friction reduction under mixed friction
• Highly suitable for components subjected to high tribological
stresses with lubricant starvation.
Applications
• Reduction in wear and friction in valve train components
(e. g. tappets)
• Anti-wear protection in diesel injection components
• Bearing components (e. g. cages) for increased life.
Triondur ® CH (hydrogen-free amorphous carbon coating)
Features: see TPI 115
Colour: iridiescent anthracite
Layer thickness
0,5 – 1 μm Friction reduction in DLC/steel compared with steel/steel
(dry in each case) 85 percent.
Hardness: > 4 000 HV.
Advantages/benefits
• Highest wear resistance of all Triondur ® coatings
• Maximum friction reduction
Applications
• Engine components
21
4
Main function – Surfaces subjected to high
tribomechanical stresses
Triondur ® CN (chromium nitride)
Features
Colour: lustrous silver-grey
Coating structure
Hard nitridic chromium coating with nanocrystalline
structure. The surface structure is smooth.
Layer thickness
1 – 4 μm.
Friction reduction in Triondur CN/steel compared with
steel/steel (dry in each case) 20 percent.
Hardness: > 2 200 HV.
Advantages/benefits
• Very high protection against abrasive wear due to
high hardness
• Friction reduction under adequate lubrication.
Applications
• Reduction in wear and friction in valve train components (e. g. tappets).
Triondur ® CNN (chromium carbonitride)
Features
Colour: matt silver
Coating structure
Multi-layer, nanodispersive, chromium-based hard
material coating.
Coating thickness: 5 – 15 μm.
Friction reduction in Triondur CNN/steel compared
with steel/steel (dry in each case) 15 percent.
Hardness: 1 200 – 1 800 HV.
Advantages/benefits
• High abrasive wear resistance due to high hardness
• Good anti-wear protection under lubricant starvation
or oil contamination.
Applications
• Reduction in wear and friction in valve train
components (e. g. hydraulic insert elements).
22
4
Main function – Surfaces subjected to high
tribomechanical stresses
Triondur ® TN (titanium nitride)
Features
Colour: lustrous gold
Coating structure
Titanium nitride
Layer thickness
2 – 5 μm.
Hardness: > 2 000 HV.
Advantages/benefits
• High anti-wear protection
Applications
• On the rib surfaces of aircraft engine bearings.
Attention!
The coating cannot be used on the bearing raceway.
23
Notes
24
MATNR 036805394-0000 / TPI 186 / GB-D / 2013031 / Printed in Germany by bresler
Schaeffler Technologies
Schaeffler Technologies
AG & Co. KG
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correctness of the information contained
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Issued: 2013, March
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TPI 186 GB-D