堆焊覆层对结构力学性能的影响分析

Influence Analysis of Surfacing Cladding on the Mechanical Properties of the Structure

针对某承压容器内表面堆焊覆层,分析了焊接残余应力、材料热膨胀性能差异、强度匹配和堆焊覆层对基体母材中裂纹前沿应力强度因子(SIF)的影响。分析结果表明,为考虑堆焊覆层的焊接残余应力,设定无应力参考温度后材料热膨胀系数数值均有所增加,其中母材热膨胀系数表述差别最大达到23.26%。因堆焊覆层中的应力明显比母材中的高,堆焊覆层对母材中裂纹前沿SIF有着显著影响。三维弹塑性有限元分析结果表明,弹塑性分析使得母材中裂纹前沿界面点SIF增加了23.83%,而设计规范中堆焊覆层对母材中裂纹前沿SIF的塑性修正存在非保守的情况。

Regarding the inner surface cladding of the pressure vessel,the welding residual stress,the difference of thermal expansion between the cladding and base metal,the strength matching and the cladding influence on the crack front stress intensity factor(SIF)in the base metal were analyzed.The resu-lts show that,considering the cladding’s welding residual stress,the thermal expansion coefficient of the material increases after setting the stress free reference temperature and the expression difference of the base metal’s thermal expansion coefficient is up to 23.26%.The stress in the cladding is significantly higher than that in the base metal,and the cladding has a significant impact on the SIF at the crack front in the base metal.The three-dimensional elastic-plastic finite element analysis results show that,the elastic-plastic properties of the material increase the crack front interface point’s SIF in the base metal by 23.83%,while the cladding’s plastic correction to the crack front’s SIF in the base metal stipulated in the design code is non-conservative.