超大型容器牛眼式局部焊后热处理模拟分析与工程应用

Simulation analysis and engineering application of bull′s eye local postweld heat treatment of ultra-large vessel

大型容器插入板与筒体传统牛眼式局部焊后热处理易发生开裂,通过有限元模拟方法分析了大型插入板与筒体焊接接头焊后热处理过程,探讨了整圈一次加热、整圈一次加热+垂直焊缝加筋板、整圈一次加热+垂直焊缝加筋板+辅助加热3种热处理工况的应力和变形情况,采用优化的焊后热处理工况进行了工程实施应用。结果表明,垂直焊缝布置加筋板可以显著改善焊后热处理过程中焊接接头及其周边区域的残余应力和变形;筋板高度和长度越大,残余应力和变形降低效果越好。研究结果为超大型容器大尺寸插入板牛眼式局部焊后热处理的工程应用提供了一种解决方法。

The bull′s eye tends to crack in the local postweld heat treatment process of the butt joint between the large-size insert plate and the cylinder of vessel,the postweld heat treatment process is analyzed by finite element simulation.The stress and deformation are discussed under three heating conditions:the once heating of the whole circle,once heating of the whole circle+the vertical weld stiffened plate,and once heating of the whole circle+the vertical weld stiffened plate+auxiliary heating.The optimized postweld heat treatment conditions are applied in engineering implementation.The results show that the arrangement of the stiffened plate on vertical weld can significantly improve the residual stress and deformation of the butt joint and its surrounding area during the post-weld heat treatment;the greater the height and length of the stiffened plate,the better the residual stress and deformation reduction effect of the butt joint area.The research results provide a solution for the engineering application of local post-weld heat treatment of the bull′s eye of large-size insert plates of ultra-larger vessel.