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US 2012/0037278 A1Published application
Rolling bearing of ceramic and steel engaging parts
AssigneeSchaeffler Technologies AG & Co. KG
InventorsOskar BEER, Franz-Josef EBERT, Gerhard KREISELMEIER, Edgar STREIT
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Abstract
A roller bearing having two cooperating rolling parts of which one is of ceramic and the other of a steel. The steel part is of such structure and/or material and/or is so produced to cause residual compressive stresses to form beneath the contact surface of the steel part, at least in a load-free state, down to a depth.
Claims4
A method of producing a steel rolling part of a roller bearing, the method comprising:
- hardening the steel rolling part by a first hardening heat treating and tempering;
- and
- subjecting the steel rolling part to a thermo-chemical heat treatment, following the tempering, by nitriding an outer layer of the steel rolling part at a temperature of at least 400° C. and thereby creating compressive stresses in a martensitic microstructure of the steel rolling part,
- wherein the tempering is performed at a temperature higher than the nitriding.
1 more element
Dependencies are inferred from the claim text.