改良9Cr-1Mo鋼溶接継手試験片内の冶金的不連続と応力再配分を考慮したクリープ疲労評価

抄録

In the next-generation fast reactor, Mod. 9Cr-1Mo steel is expected as a structural material of the steam generator, and in the design of a large tank reactor, it is inevitable to place the weld bead on the high stress part. Therefore, a creep-fatigue evaluation method that can appropriately evaluate weld joint is required. The welded joint is composed of a base metal, weld metal and heat-affected zone. In this study, finite element analysis considering these material property differences was performed on the test piece of the welded joint. And the creep fatigue life was evaluated based on the stress redistribution during the test. Our evaluation method was able to predict the number of failures in the fatigue test and creep fatigue test within the factor of 10.