Evaluation of Local Tensile Properties of Bi-metallic Weld Joints by Small Tensile and Ball Indentation Tests

摘要

This study performed tensile test using small-size flat specimen and ball indentation test at room temperature to characterize the local tensile properties of bi-metallic weld joints. The weld specimens used were fabricated by joining between SA508 Gr.3 ferritic steel and Type 316 stainless steel with Alloy 82 buttering on the ferritic steel side and Alloy 82/182 weld metal. The test results showed that yield stress (YS) of weld metal was slightly higher than that of Type 316 and smaller than that of SA508 Gr.3, and ultimate tensile stress (UTS) of weld metal was similar as those of Type 316 and SA508 Gr.3 base metals. Also, the values of YS and UTS of buttering layer (Alloy 82) were nearly same as those of weld metal. Heat-affected-zones (HAZs) showed higher YS and UTS values compared to their base metals. Especially, the strengths of SA508 Gr.3 were significantly higher than those of surrounding materials. Also, it was known that the ball indentation test reasonably measured the local YS and UTS of bi-metallic weld joints.