Enhanced Surface Hardness by Boron Diffusion in Martensitic Stainless Steel via Cathodic Reduction and Thermal Diffusion Based Boriding (CRTD-Bor)

Abstract

In this study, a developed new boriding method called as “Cathodic Reduction and Thermal Diffusion based Boriding” (CRTD-Bor) was applied to increase the surface hardness of 400 series steels. The cross-sectional examination of borided steel revealed that the boride layers consisted of single phase Fe2B. A dense and continuously 25μm thick Fe2B layer could be formed after 20 minutes of CRTD-Bor. The grown boride layer exhibited 1500±200 HV on top, and gradually decreased to the matrix (325 ± 25 HV).