Use of New Toughness Parameters from the Tensile Test Application in Characterising the Heat-Affected Zone in Weld Joints

A simple test procedure that can substitute the Charpy test for the estimation of ductile fracture toughness of the weakest region of a weld joint has been evolved. This approach explocits the conventional tension test with smooth round specimens, and stipulates that the post necking regime in this test is dominated by micro-void growth and coalescence processes. The method of computing two new toughness parameters from the load-elongation data of the tensile test is described. The effect of aging of the 2.25 Cr - 1 Mo steel HAZ in the Alloy 800/2.25 Cr - 1 Mo steel dissimilar metal joint (welded with inconel 182 electrodes) was studied to demonstrate the application, efficacy and sensitivity of these estimates of fracture toughness.