Method and device for heat treatment of metal workpieces as well as a heat-treated workpiece

Abstract

A process for heat treating metal workpieces contains with respect to an efficient process control the following successive operations following directly one after the other: a heating phase; an enrichment phase; a first cooling phase; a boriding phase; a second cooling phase; and a concluding quenching phase. Workpieces processed by a method of this type are distinguished by a comparatively great fatigue limit and fatigue strength with simultaneous high resistance to wear and tear.

1 . Workpiece that is made of a metal material and is heat treated, the workpiece comprising: 
 an outer iron boride layer from 10 μm to 100 μm thick and a case hardening layer beneath the iron boride layer with a Vickers hardness between 600 and 900 and a case hardening depth between 0.2 mm and 2.0 mm.