Surface nano-alloying treatment of low carbon steel

Abstract

A nano-structured alloying layer was fabricated by the addition of 304 stainless steel powder to the surface of a low carbon steel (LCS) plate by surface mechanical attrition treatment (SMAT). The coverage of the stainless steel layer was 93 % after SMAT for 60 min. The thickness of the surface layer was approximately 35 µm. The average grain size in the top layer was in the range of 55-65 nm with random crystallographic orientation, and the grain size increased with increasing depth from the treated surface. Both the surface hardness and wear resistance of the sample that underwent a surface nano-alloying treatment (SNAT) increased compared with those of the LCS sample. Additionally, the wear resistance increased for the nanocrystalline (nc) surface layer. Nanoindentation measurements indicated that micro-hardness in the nc surface layer was approximately 645 HV, which was three times as high as that of the LCS matrix.