Localized corrosion of AISI 316L S.S in Arabian Gulf seawater

Abstract

An investigation has been carried out to evaluate the localized corrosion behavior such as pitting and crevice corrosion of AISI 316L in Arabian Gulf seawater. The immersion test and electrochemical techniques were utilized to study the different factors affecting the localized corrosion. The maximum pit depth appears to be a linear function of exposed area and exposure time. An increase in temperature causes a decrease in pitting potential, and increase in corrosion rate and pitting tendency. The kinetic of passive film formation at corrosion potential of 316L stainless steel is slow, and the slow scan rate lets the film thickening to occur, therefore, the slow scan rate is most suitable to study the localized corrosion using potentiodynamic pitting test. The results show that more homogeneous is the surface, higher the pitting potential and lesser the pit depth. The immersion test was utilized to evaluate the effect of crevice formers and crevice geometry on the crevice corrosion of AISI 316L S.S. The effect of crevice formers and crevice geometry on the initiation time of crevice corrosion was studied by monitoring the corrosion potential with time. The influence of temperature on the crevice corrosion was investigated by studying the critical crevice corrosion at elevated temperatures. The mechanism of corrosion has been discussed.