The Effect of Grain Size of Steel R6M5 on the Diffusion Rate and Growth Kinetics of the Hardened Layer After Ion Nitriding in a Glow Discharge

The work is devoted to studying the effect of grain size and morphology of R6M5 high-speed tool steel on the microstructure and microhardness after ion nitriding in a glow-discharge. It has been established that the use of severe plastic deformation torsion before ion nitriding forms a highly fragmented and disoriented ultrafine-grained structure, which contributes to an increase in the surface microhardness and the thickness of the diffusion layer on high-speed tool steel R6M5.