材料期刊网

采用有限元模拟的方法,对厚壁316LN不锈钢管焊接接头中的焊接残余应力进行研究,分析了焊道合并对模拟结果的影响,并采用X射线应力测试对模拟结果进行了验证.结果表明:在考虑钢管初始应力的条件下,模拟结果与实测结果吻合;轴向残余拉应力主要出现与盖面焊道毗邻的钢管外壁以及最后一道盖面焊道下方,其中钢管焊接在工装上、受工装拘束较大的管道一侧,拉应力数值和范围都较大;焊道合并简化对残余压应力的分布和数值影响较大,对主要分布在盖面焊道附近的残余拉应力的影响较小;选择合适的简化模型可以在保证较高计算准确度的同时缩短计算耗时,可用于大型焊接结构残余应力场的模拟.

The welding residual stress in welded joint of thick-walled 316LN stainless steel pipes was studied by finite element modeling, and the influence of lumped pass on simulation results was analyzed.At last, simulated results were verified by X-ray diffraction stress measurement.The results show that the simulated results were corresponded with measured results if initial stress of pipes was considered.The axial residual tensile stress is found near the cosmic weld beads and located at the region that below the last weld bead.The value of tensile residual stress is higher and its distribution region is larger.The lumped pass method had a great influence on the distribution and value of residual compressive stress rather than the residual tensile stress that distributed across the cosmic welds.Reasonable lumped pass model is suitable for welding residual stress simulation of large-scale welding structure for its efficiency and reliable accuracy.