Welding residual stress ( WRS) is an important factor that promotes stress corrosion cracking in dissimilar metal welds ( DMW) of nozzle safe end .This study aims to investigate the effects of safe end length,boundary conditions (BC) during welding and similar metal welding (SMW) on WRS in DMW by finite element analysis.The results show that for short safe end (w/t=0.5),adoption of clamped condi-tion is favorable to reduction of axial residual tensile stress on the inner surface of DMW ,and the axial re-sidual tensile stress will be greatly reduced after SMW;for long safe end (w/t=4.0),axial residual ten-sile stress on the inner surface of DMW is insensitive to the clamped condition on safe end side , after SMW,the axial residual tensile stress on inner surface of DMW will be increased .%焊接残余应力是造成接管安全端异种金属焊缝发生应力腐蚀开裂的重要因素.利用有限元方法,主要研究了安全端长度、焊接约束条件和同种金属焊接对异种金属焊接残余应力的影响.结果表明,安全端较短(w/t=0.5)时,安全端侧采用固定约束有利于减小异种金属焊缝内表面的轴向残余拉应力,经同种金属焊接后,异种金属焊缝内表面的轴向残余拉应力会大幅降低;安全端较长(w/t=4.0)时,异种金属焊缝内表面的轴向残余拉应力对安全端侧的约束条件不敏感,经同种金属焊接后,异种金属焊缝内表面的轴向残余拉应力会增大.
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