Patent ID: 6264768
Filing Date: 2001-07-24
Classification: C21D

Abstract:
A method of net shaping raceways of high performance rolling element bearing races comprising the steps of:(a) heating a workpiece in the form of a near net shaped bearing race blank having a rolling element engagement surface with a case above its critical temperature to obtain an austenitic structure throughout its hardened case. the engagement surface intended for engagement by a plurality of rolling elements;(b) quenching the workpiece at a rate greater than the critical cooling rate of its case to a uniform metastable austenitic temperature above the martensitic transformation temperature;(c) holding the temperature of the workpiece at the uniform temperature while crowning the engagement surfaces of the workpiece between spaced lateral surfaces and maintaining the engaging surfaces of rolling dies flat or crowning the engaging surfaces of the rolling dies and maintaining the engagement surfaces of the workpiece flat, then rolling the engagement surface between a pair of the opposed rolling dies to a desired shape before martensitic transformation occurs; and(d) cooling the workpiece through the martensitic range to harden the engagement surface.