Fracture Toughness Evaluation on Stainless Steel Welds by Tensile Tests with Circumferentially Notched Round Bar Specimen

Abstract

Local fracture toughness of top, middle, bottom, and heat-affected zones of weld joints of SUS304L and SUS316L have been evaluated by a new testing procedure of J-evaluation on tensile test (JETT) with circumferentially notched round bar specimen. Delta (δ)-ferrite contents of those welds were changed between 0% and 10%. The tests were carried out at 4K. Fracture toughness at 4 K obtained by JEIT was a little bit higher than that obtained by conventional CT specimens as was lower in weld metals than in base metals and decreased as the content of δ-ferrite increased in both 304L and 316L. Scatter in the values of fracture toughness among the locations in weld metals were considered to be caused by effects of δ-ferrite grains.