Patent ID: 8844140
Filing Date: 2014-09-30
Classification: F16C,Y10T

Abstract:
1. 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 plasma nitriding an outer layer of the steel rolling part at a temperature of at least 400° C. so that compressive stresses in a martensitic microstructure of the steel rolling part of at least 300 MPa for a load-free outer layer of the steel rolling part from a surface to a depth of 40 μm from the surface are created and so that the outer layer has a hardness of at least 800 HVO.3 at a depth of about 0.2 mm from the surface, wherein the tempering is performed at a temperature higher than the nitriding.