DUPLEX HARDENING PROCESS AND ARTICLES MADE THEREFROM

摘要

A process for hardening steel workpieces and articles made therefrom, such as bearing rings, rolling elements, gears, cams, splines and lifters, comprising the steps of subjecting a workpiece steel to at least two sequential process segments wherein each process segment consists of subjecting the workpiece to a Boost period in an atmosphere containing active nitrogen, then subjecting the workpiece to a Diffuse period in an atmosphere free of active nitrogen to provide a desired target nitrided case depth in the steel workpiece in less time than in the prior art duplex hardening process with no deleterious intergranular network formation in the surface region.