Structure and Properties of Multicomponent Diffusion Boride Coatings Formed on a Hardened 30KhGSA Steel Surface

The microstructure and microhardness of multicomponent diffusion boride coatings formed on the surface of prehardened 30KhGSA steel have been studied. Diffusion coatings on prehardened 30KhGSA steel have been obtained by simultaneous diffusion saturation with boron, chromium, titanium, and silicon. Metallographic analysis has been carried out on a Carl Zeiss Axio Observer Z1m metallographic microscope in the ThixoMet PRO software package. The efficiency of the multicomponent boriding process combined with the hardening has been demonstrated. The prehardening of 30KhGSA steel makes it possible to obtain higher microhardness indices as compared with the case of complex boron‒chromium‒titanosiliciding without prehardening. Under thermal treatment, the surface microhardness of the diffusion coating decreases from 1980 to 1160 HV0.1. This is accompanied by an increase in the diffusion-coating thickness by a factor of 3.