Corrosion and mechanical properties for Cr-coated CSS-42L bearing steel after Ti and C ions co-implantation

In this work, the effects of (Ti + C) co-implantation on the corrosion resistance and mechanical properties of Cr-coated CSS-42L bearing steel were described. Single Ti and C ion implantation were also applied for comparison. The corrosion behavior and mechanical properties of implanted samples were investigated by nanoindentation and potentiodynamic polarization tests. Film structures and phase transitions had been characterized by GAXRD, AES, XPS, SEM and TEM. The current density and corrosion rate of Cr-coated CSS-42L bearing steel after ion implantation were reduced obviously, especially for (Ti + C) co-implanted samples which were more than 10 times lower than that of the untreated samples. It was also noticed that the Young's modulus of Cr coating after (Ti + C) co-implantation decreased, meanwhile its nanohardness improved significantly. The corrosion resistance and mechanical improvement were attributed to the formation of irradiated amorphous phase and ceramic phases Cr₂C/TiC.