压水堆蒸汽发生器安全端在焊接过程中会产生较大的残余应力，而焊接残余应力是导致安全端焊接接头产生应力腐蚀开裂的主要原因之一。焊接接头残余应力大小和分布受到几何结构和焊接热应力等因素的影响。为了了解压水堆蒸汽发生器安全端异种金属焊接接头残余应力的大小和分布情况，本文采用ABAQUS软件对压水堆核电站蒸汽发生器安全端焊接过程进行数值仿真分析，主要研究内容如下： 以异种金属平板对接焊为研究对象，建立了焊接结构三维有限元模型，编制了DFLUX热源模型，并利用ABAQUS软件计算得出了焊接过程中的瞬时温度场；通过分析瞬时温度场中的热源分布和热循环曲线，得出了焊接过程温度场的分布特征；采用顺序耦合方法将温度场以热载荷的形式加载到应力分析模型，得到了异种金属平板对接焊残余应力场分布规律。 采用1/8圆筒对接焊简化模型，以及考虑实际焊接环境下热载荷和力学边界条件的前提下，对压水堆蒸汽发生器安全端异种金属焊接接头的温度场和残余应力场进行了数值模拟分析。得出了蒸汽发生器安全端焊接过程中瞬时温度场分布特征和残余应力场分布规律。 本研究为准确分析压水堆蒸汽发生器安全端异种金属焊接接头残余应力分布提供了一定的基础，也为安全端焊接接头应力腐蚀开裂及疲劳断裂的分析提供一定参考。

Residual stress are usually produced in the welding process of pressurized water reactor (PWR) steam generator safety end, which is one of the main reasons of stress corrosion cracking. The intensity and distribution of residual stress is affected by the geometric structure and welding heat stress of the welding joints. To further research the intensity and distribution of residual stress at the dissimilar metal welding joint of PWR steam generator safety end, ABAQUS software was used to carry on main contents below as follows: Object to the metal tablet butt welding, a three-dimensional infinite element model of the welding structure and a DFLUX heat source model were built. In addition, the transient temperature field during the welding process was calculated by ABAQUS. With the analysis of the heat source distribution of transient temperature field as well as the heat recycle curve, the distribution characteristics of the temperature field during the welding process was obtained. The temperature field was loaded to the residual stress analysis model by sequential coupling method, and the distribution of dissimilar metal tablet butt welding residual stress field was calculated. A eighth cylinder butt welding simplified model was created by taking into account thermal load in the real welding environment and the mechanical boundary conditions, the temperature field and residual stress field of dissimilar metal welding joints in the PWR steam generator safety end was also analyzed. The distribution characteristics of transient temperature field and the distribution law of residual stress during the welding process of PWR steam generator safety end were thus obtained. This thesis provides some basic knowledge for study of residual stress distribution of dissimilar metal welding joints in the PWR steam generator safe end, which offers reference to the analysis of safety end welding joints stress corrosion cracking and fatigue fracture.