Effect of electrochemical potential on tribocorrosion behavior of low temperature plasma carburized 316L stainless steel in 1 M H2SO4 solution

Low temperature plasma carburizing is a surface engineering technique developed for austenitic stainless steels to achieve combined improvements in tribological and corrosion resistant properties. However, very little work has been conducted to study the response of carburized stainless steel to combined actions by wear and electrochemical corrosion. In the present work, experiments have been conducted to study the tribocorrosion behavior of low temperature plasma carburized AISI 316L stainless steel, under unidirectional sliding in 1 M H2SO4 solution, using a pin-on-disk tribometer integrated with a potentiostat for electrochemical control. Sliding wear tests were conducted under potentiodynamic and potentiostatic conditions at a wide range of applied potentials. It is found that the carburized layer exhibits much better tribocorrosion resistance than the untreated specimen at anodic potentials, but is not effective in improving wear resistance at cathodic potentials. The results are discussed in terms of the accumulation of the third body wear particles, material transfer and the contribution of mechanical wear and chemical wear to overall material removal by tribocorrosion.