焊接残余应力的温度-组织-应力耦合分析

Thermal-mechano-metallurgical coupled analysis of welding residual stress

在应变加和分解式的基础上,通过引入相变应变增量描述模型,采用均匀化方法对多相组织力学行为进行描述,构建可以对温度-组织-应力耦合关系进行表征的模型,并将该模型应用于对9Cr1Mo钢管道环焊缝接头焊接残余应力的分析中.结果表明,在数值模拟中,使用三维有限元模型进行计算,计算结果很好的体现了在焊接过程中马氏体相变随热源移动逐渐进行的过程.在对焊接残余应力的表征上,无论是在残余应力沿管道轴向分布的特征,还是在具体的残余应力水平上,三维有限元计算的结果均与实际测量结果取得了较好的吻合.

By including the increment of transformation strain into the additive decomposition of the increment of total strain,the constitutive model for thermo-mechano-metallurgical analysis was founded.In this model,the behavior of inhomogeneous multiphase mixture was described by using a homogenizing method.On the basis of the model,the welding residual stress in tubular joint of 9Cr1Mo steel was analyzed by using finite element method.In the numerical simulation,a three-dimensional finite element model is used.The calculated results show that the martensitic transition in tubular joint gradually occurs with the movement of welding heating source.As far as the welding residual stress from the three-dimensional analysis is concerned,both the distribution of it in the axial direction of pipeline and the detailed value of it have a good agreement with the experimental results.