4024 Q^*コンセプトに基づく9%Crフェライト系耐熱鋼溶接継手材のクリープき裂成長速度評価(S25-5 寿命評価,S25 材料・構造の非弾性挙動・高温強度・損傷評価)

抄録

Creep crack growth behavior is very sensitive to the variation of materials micro structures such as the heat affected zone of weld joint. This is a main issue to be clarified for 9%Cr ferritic heat resistant steel concerning the application of actual component structure. In this paper, high temperature creep crack growth tests were conducted on CT specimens with crack in the heat affected zone of weld joint of W added 9%Cr ferritic heat resistant steel (ASME Code: P92). The creep crack growth behavior in the heat affected zone of weld joint was investigated. On the basis of Q^* concept, the algorithm of predicting the life of creep crack growth was proposed. Furthermore, 3-dimensional elastic-plastic creep FE analyses were conducted and the effect of stress multi-axiality of welded joint on creep crack growth rate was discussed as compared with that of base metal.