Improvement on hardness and corrosion resistance of ferritic stainless steel via PVD-(Ti,Cr)N coatings

SUS 430 ferritic stainless steel shows poor performance in corrosion resistance when compared with austenitic stainless steels, thus the material has limited actual application. In this study, SUS 430 stainless steel was selected as the experimental substrate, and a PVD method, cathodic arc deposition, was used to deposit single-layered TiN, CrN and multilayered TiCrN coatings on the substrate. Properties including hardness and corrosion resistance were analyzed and compared before and after coating treatment to explore the efficiency of surface modification. The results showed that the SUS 430 stainless steel coated with the multilayered TiCrN films had not only a great increase in surface hardness (from 160 to 2852kg/mm2), but also an improvement in corrosion resistance in 10vol.% HCl solution (weight loss equals 45×10-6g and 8×10-6g for uncoated and TiCrN films, respectively).