Improvement in Tribocorrosion Behaviour of 304 Stainless Steel by Surface Mechanical Attrition Treatment

The tribocorrosion behavior of surface mechanical attrition treated (SMAT) AISI 304 stainless steel by spherical shot peening has been investigated under combined electrochemical and unidirectional sliding conditions in 0.9% NaCl solution. Sliding wear tests of both treated and untreated specimens were conducted under potentiodynamic, open circuit and potentiostatic conditions. It was found that under all test conditions, SMAT was effective in reducing material removal by 2 to 4 times and reducing coefficient of friction against an alumina slider. Detailed analysis showed that SMAT was effective in reducing both mechanical wear and chemical wear during tribocorrosion. The much improved tribocorrosion behavior can be attributed to the surface hardening effect of the surface layer induced by surface mechanical attrition treatment.