HR3C/T91异种耐热钢焊接接头界面蠕变失效有限元模拟  

Numerical simulation on interfacical creep failure of dissimilar welded joint between HR3C and T91 heat-resistant steels

作　　者：张建强[1] 张国栋[1] 郭嘉琳[1] 

机构地区：[1]武汉大学水射流理论与新技术湖北省重点实验室,武汉430072

出　　处：《焊接学报》2017年第10期11-15,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51374154)

摘　　要：利用有限元方法对HR3C/T91接头在温度为600℃、内压为42.26 MPa作用下的最大蠕变主应力、von Mises等效应力和应力三轴度进行数值分析,并采用温度—应力双参数加速试验对模拟结果进行验证.结果表明,最大主应力峰值位于管接头内表面焊缝/T91界面附近区域,von Mises等效应力峰值同样位于内表面焊缝/T91界面附近区域,因而焊缝/T91界面区域内孔洞易于形核、扩张.内表面应力三轴度峰值分别位于HR3C/焊缝和焊缝/T91界面处,与两界面重合.内表面焊缝/T91界面处的应力三轴度数值较大,而焊缝/T91界面的蠕变强度较HR3C/焊缝弱,因此焊缝/T91界面为接头的薄弱环节,与加速试验结果一致.The maximum principal stress,von Mises equivalent stress,stress triaxiality in dissimilar welded joints between austenitic( HR3C) and martensitic heat-resistant steel( T91) are simulated by FEM under the conditions of 600 ℃ and inner pressure of 42. 26 MPa. The results show that the maximum principal stress and von Mises equivalent stress are quit high in the vicinity of weld/T91 interface,creep cavities are easy to form and expand in the weld/T91 interface. Weld/T91 interface is the weakest part of welded joint. The stress triaxiality peak is located exactly at the weld/T91 interface,and quit high.Therefore,using stress triaxiality to describing creep cavity nucleation and expansion and crack development is reasonable for the dissimilar welded joint between austenitic and martensitic steel.

关 键 词：异种钢接头 有限元 最大主应力 等效应力 应力三轴度 

分 类 号：TG407[金属学及工艺—焊接]