A comparison between mechanical and tribological properties of coarse- and nano-grained austenitic stainless steel

The mechanical and tribological properties of coarse-grained (CG) and nano-grained (NG) 301 stainless steels were evaluated and compared together. For this purpose, room temperature tensile and reciprocating wear tests were used. FESEM and EBSD analysis, XRD and Feritscope measurements were done for the characterization of materials. Results showed that the yield and tensile strength of the NG sample were respectively 2.3 and 1.27 times higher and toughness was slightly increased compared with the CG sample. Significant work-hardening occurred in two different stages during the tensile test of both samples. Wear resistance decreased at increasing the amount of surface martensite. So, more surface martensite in the NG sample resulted in less resistance to wear. For both grain size conditions, the wear mechanism was changed from adhesive to oxidative wear with increasing the sliding distance. (paper)