The effect of heat treatment on corrosion behavior of laser surface melted 304L stainless steel

Laser surface melting (LSM) improves the passivation and pitting behavior of 304L stainless steel. This improvement was attributed to microstructural modification, mainly to increased δ-ferrite content, and elimination and/or redistribution of sulfur based inclusions. In this study, in order to clarify the role of microstructural changes that took place during LSM on electrochemical behavior, laser surface melted 304L grade stainless steel was heat treated at 1050 °C. A detailed analysis of the electrochemical behavior of as-received, laser surface melted and laser surface melted + heat treated 304L in sulfuric acid and sodium chloride solutions was conducted. Effects of laser surface melting and post heat treatment on pit morphology was also investigated.