Enhancement of intergranular corrosion resistance of type 304 stainless steel through a novel surface thermo-mechanical treatment

An experimental study is carried out on a novel surface thermo-mechanical treatment involving conventional shot blasting and laser surface treatment, for enhancing inter-granular corrosion resistance of type 304 stainless steel. The modified surface exhibited fine re-crystallized austenite grains. A non-destructive approach of monitoring width of γ(311) diffraction peak through a portable X-ray diffraction was adopted, to determine micro-structural state on the thermo-mechanically treated surface. The results of the study have demonstrated that laser-assisted surface thermo-mechanical treatment of type 304 stainless steel is effective not only for enhancing materialʹs inherent resistance against sensitization and inter-granular corrosion due to its subsequent exposure to susceptible temperature regime but also for reducing inter-granular corrosion susceptibility of pre-sensitized specimens.