Improved pitting corrosion resistance of cold worked and thermally aged AISI type 316 L(N) SS by laser surface modification

Abstract

Laser surface melting has been conducted on the surface of prior cold worked and aged AISI type 316 L(N) stainless steel specimens to homogenise the composition and as a result improve the corrosion resistance. Although the top layers of surface melted specimens did not show a marked improvement in corrosion resistance, the subsequent layers exposed after mild polishing showed a dramatic increase in pitting corrosion resistance and an appreciable improvement in intergranular and general corrosion. This is attributed to the dissolution of secondary phases in the melted and heat affected zones.

Keywords:

• LASER SURFACE MODIFICATION
• PITTING CORROSION
• AISI TYPE 316 L(N) SS
• EPR TEST