超超临界机组奥氏体/马氏体异种钢接头蠕变数值模拟  

Creep numerical simulation on dissimilar welded joint between austenitic and martensitic heat-resistant steel in USC power plant

作　　者：李太江[1] 姚兵印[1] 刘福广[1] 张建强[2] 章应霖[2] 

机构地区：[1]西安热工研究院有限公司,西安710032 [2]武汉大学动力与机械学院,武汉430072

出　　处：《焊接学报》2011年第7期79-82,117,共4页Transactions of The China Welding Institution

基　　金：湖北省自然基金资助项目(2007ABA040)

摘　　要：采用有限元方法对超超临界火电机组中新型奥氏体耐热钢HR3C/马氏体耐热钢T91异种钢接头在600℃/42.26 MPa内压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了数值模拟.结果表明,对于HR3C/T91异种钢接头,最大主应力峰值位于焊缝/T91界面附近区域,蠕变孔洞易于在焊缝/T91界面区域形成;von Mi-ses等效应力峰值同样位于焊缝/T91界面附近区域,因而,焊缝/T91界面区域内的蠕变孔洞易于扩张;应力三轴度的峰值分别位于HR3C/焊缝和焊缝/T91界面处,与界面重合.焊缝/T91界面处的应力三轴度数值较大、变化较小,采用应力三轴度可以更准确地描述HR3C/T91异种钢接头界面蠕变孔洞扩张及裂纹扩展特性,焊缝/T91界面为接头的薄弱环节.The maximum principal stress,von mises equivalent stress and 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 describe creep cavity nucleation and expansion and crack development is reasonable for the dissimilar welded joint between austenitic and martensitic steel.

关 键 词：奥氏体耐热钢 马氏体耐热钢 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]