Corrosion properties of Stainless steel

Abstract

Chromium content in austenitic stainless steel 304 and 316L can increase the resistance to pitting corrosion through the formation of passive layer on the surface of metal. The corrosion properties of these stainless steels in the chemical mediums with different concentrations are determined through electrochemical method using potentiostat. The experiment is done in sodium chloride solution 3.5 wt%, 5.0 wt%, 10.0 wt%, and 0.1M H2SO4 respectively. It was found that AISI 316 has higher corrosion resistance compared to AISI 304. The results shows that the corrosion rate of stainless steels was increase in H2SO4 solution compared to NaCl solution. The experimental results shows that the corrosion rate was increase accordingly to the solution concentration. Microstructure analysis that have been done using optical microscope and scanning electron microscope shows that the increases number of pitting occurs when subjected to a high concentration of chloride ions.