Solidification Cracking of High Speed TIG and Laser Welds in Austenitic Stainless Steel Sheet

TWI Industrial Member Report Summary 224/1983

By J Honeycombe and T G Gooch

Background

The application of high travel speeds for TIG and laser welding austenitic stainless steel sheet has been examined. with particular reference to solidification cracking behaviour. Welds were made at 800-1500mm/min and 1000-6000mm/min for the TIG and laser processes respectively. With both processes, increased travel speed promoted cracking, the threshold speed for sheet of similar thickness being higher for laser welds. Ferrite was beneficial in reducing cracking sensitivity, but its effect was limited by segregation during solidification which led to local areas solidifying to austenite even in materials of high Cr_eq/Ni_eq ratio.