Nitriding of high speed steel

Abstract

Current practice when nitriding high speed steel (HSS) cutting tools is to avoid embrittlement of the cutting edge by limiting the depth of the diffusion zone. This is accomplished by reducing the nitriding time and temperature and eliminating any compound layer formation. However, in many applications there is an argument for generating a compound layer with beneficial tribological properties. In this investigation, results are presented of a metallographic, X-ray diffraction and X-ray photoelectron spectroscopy analysis of nitrided HSS surface layers generated using active screen plasma nitriding and reactive vapour deposition using cathodic arc. These results are discussed in the context HSS cutting tool performance when machining under built-up edge conditions.