焊接残余应力对Invar钢疲劳寿命影响分析  

Effect of welding residual stress on fatigue life of Invar steel welded joint

作　　者：赵东升[1] 吴国强[2] 刘玉君[1] 刘文[1] 纪卓尚[1] 

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室船舶工程学院,大连116024 [2]大连理工大学工业装备结构分析国家重点实验室航空航天学院,大连116024

出　　处：《焊接学报》2013年第4期93-95,108,共4页Transactions of The China Welding Institution

基　　金：教育部高等学校博士学科点专项科研基金资助项目(20120041120015);中央高校基本科研业务费资助项目

摘　　要：利用有限元软件MSC.Marc计算了液化石油天然气船液舱Invar钢薄膜的焊接温度场和残余应力场,并计算了焊接残余应力与液体晃荡压力耦合条件下焊缝处的疲劳寿命.结果表明,焊缝表面中心线上的节点的纵向残余应力可达298.1 MPa左右,焊缝纵向残余应力的峰值可达328.3 MPa左右,高于Invar钢的室温屈服强度280.1 MPa.由于焊接残余应力的存在,Invar钢薄膜焊缝的疲劳寿命约由2.1×106降低到1.7×105.The temperature field and residual stress field in the Invar steel film of LNG ship tank was numerically simulated using finite element software MSC.Marc, and the calculation of fatigue life of the welded joint was carried out with the welding residual stress field coupled with the liquid sloshing pressure. The calculated results show that the longitudinal residual stress in the centerline on weld surface was about 298 MPa, and the peak value of longitudinal residual stress reached 328 MPa, higher than the yield strength (280 MPa) of the Invar steel at room temperature. Because of the existence of the welding residual stress, the fatigue life of Invar steel welded joint decreased from about 2.1×106 to 1.7×105.

关 键 词：INVAR 钢 焊接残余应力 晃荡 疲劳寿命 

分 类 号：TG405[金属学及工艺—焊接]