大厚度奥氏体不锈钢筒体填丝激光焊接变形和应力分析

目的 研究大厚度奥氏体不锈钢筒体填丝激光焊接，优化结构设计和工艺设计。方法 建立大厚度奥氏体不锈钢筒体填丝激光焊接数值分析模型，通过数值模拟的方法，定量分析大厚度奥氏体不锈钢筒体焊接变形和应力。结果 零件下部38 mm厚焊缝位置处的最大径向收缩量为1.2 mm;零件下部60 mm厚焊缝位置处的最大径向收缩量为2.0 mm;零件中部60 mm厚焊缝位置处的最大径向收缩量为1.9 mm;零件上部60 mm厚焊缝位置处的最大径向收缩量为1.8 mm。填丝激光焊接轴向收缩量为0.55 mm。焊接残余应力最大值在450 MPa左右，应力主要分布在焊缝附近。热处理后，焊接残余应力都有明显降低，最大残余应力从450 MPa左右降低到200 MPa左右，焊接残余应力范围存在一定程度减小;焊接残余变形变化较小，热处理后某些位置的变形略微有所增大。结论 模拟结果表明，大厚度奥氏体不锈钢筒体填丝激光焊接变形和应力在可接受范围内，焊后热处理对释放残余应力有重要作用。

Deformation and Stress in Wire-fed Laser Beam Welding of Thick Austenitic Stainless Steel Cylinders

The work aims to study the wire-fed laser beam welding of large-thickness austenitic stainless steel cylinders, and optimize their structural design and process design. A numerical analysis model for wire-fed laser beam welding of large-thickness austenitic stainless steel cylinders was established. Through numerical simulation, the welding deformation and stress of large-thickness austenitic stainless steel cylinders were quantitatively analyzed. The maximum radial shrinkage at the weld location of 38 mm thick at the lower part of the part was 1.2 mm. The maximum radial shrinkage at the weld location of 60 mm thick at the lower part of the part was 2.0 mm. The maximum radial shrinkage at the weld location of 60 mm thick at the middle part of the part was 1.9 mm. The maximum radial shrinkage at the weld location of 60 mm thick at the upper part of the part was 1.8 mm. The axial shrinkage of wire-fed laser beam welding was 0.55 mm. The maximum residual stress of the part after wire-fed laser beam welding was around 450 MPa, and the stress was mainly distributed near the weld. After heat treatment, the welding residual stress significantly reduced, with the maximum residual stress decreasing from around 450 MPa to about 200 MPa, which indicated a certain degree of reduction in the range of welding residual stress. After heat treatment, the change in welding residual deformation was minor, and deformation at certain locations slightly increased after heat treatment. The simulation results show that the deformation and stress of wire-fed laser welding of large-thickness austenitic stainless steel cylinders are within an acceptable range, and post-weld heat treatment plays a significant role in releasing residual stress.