| 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. |
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