A Comparative Stress Corrosion Cracking Study of Stainless Steel Sheets Marked with Laser and Conventional Mechanical Stamping

This communication reports the result of a comparative study of laser marking with conventional mechanical stamping of AISI 304 stainless steel sheet by subjecting the marked specimens to stress corrosion cracking susceptibility test. A single mode fiber laser was made use of for this work to mark the steel specimens while a hydro-pneumatic press was used to effect marking in the conventional way. Mechanically stamped specimens exhibited better resistance to stress corrosion cracking compared to specimens marked with laser. The cracking susceptibility of laser marked samples was found to be critically dependent on the fluence of laser used to cause marking. Extent of cracking was found to increase with fluence. Reduced stress corrosion cracking susceptibility of mechanically stamped specimens was attributed to the presence of compressive residual stresses in and around the mark. This work establishes that upon scaling down its fluence appropriately, a laser can be a workable tool for marking stainless steel components meant for application in corrosive media.