Evaluation of pitting susceptibility and tribocorrosion behaviors of AISI 304 stainless steel in marine environments

Abstract

There is an increasing concern over simultaneous wear and corrosion (tribocorrosion) issues that cause the material failure of stainless steel in marine environments. The main objective of this study is to understand the effect of tribocorrosion conditions on pitting susceptibility and synergistic material loss for AISI 304 stainless steel. For this purpose, tribocorrosion tests were conducted in a natural seawater-filled corrosion cell integrated with a tribometer. An alumina ball of 6 mm radius slid against AISI 304 stainless steel plates under 5 N and 7.5 N loads in natural seawater. The cyclic polarization scans were carried out under corrosion and tribocorrosion conditions in the natural seawater by applying different loads. Also, tribocorrosion tests were conducted under anodic (0.3 V), cathodic (−0.5 V) and Open Circuit Potential (OCP) to determine the effect of electrochemical potential on pitting susceptibility and material loss rate. The study revealed that electrochemical potential significantly affects pitting corrosion and material loss, and the material losses increased significantly from the cathodic potential to the anodic potential. Furthermore, the material loss of AISI 304 alloy during tribocorrosion in natural seawater due to corrosion was significantly lower than wear. The wear-corrosion synergism played an essential role in total material loss, confirming that wear and corrosion affect accelerated material loss positively. The material loss of AISI 304 is mainly due to pure mechanical wear and corrosion-induced wear.