応力除去焼なまし割れ評価法の提案

抄録

Usually, stress relief annealing (SR) treatment among various PWHT (post weld heat treatment) are widely performed for the purpose of removement of the welding residual stress and softening of the welded joint. However, a crack (namely SR-crack) at the notch of the coarse grained zone in the heat affected zone (HAZ) of the welded joint may be produced anew by SR-treatment although it improves the quality of the welded joint.
In this paper, making a comparison of the mechanical behavior during SR-treatment between with the notch and without one at the coarse grained zone in HAZ of the welded joint, the influences of the existence of the notch on the stress-strain are clarified. Moreover, a mechanical measure for the reheat crack (SR-crack) is proposed and an evaluating method for it is shown from a mechanical point of view.