Strain distributions in a type 316/16-8-2 stainless steel weldment during cyclic loading

Test specimens were cut from a 25-mm thick Type 316 stainless steel plate butt welded with 16-8-2 filler wire. The specimens were oriented transverse to the weld seam and contained base metal, heat-affected zone (HAZ), and weld metal in the gage section. Strain-controlled cyclic loading was imposed across the heterogeneous weldment while local strains at various points within the gage section were continuously monitored. Results show that strains at the local points can vary markedly from the average strain of the composite section. Strain concentrations occurred in the softer base metal which led to failure much sooner than the composite strain would indicate. However, when the maximum strain range from a local area was compared to baseline data, the life correlation was very good.