瞬态热拉伸强度对304L不锈钢焊接变形影响的计算分析  

Computation and Analysis of the Influence of Transient Thermal Tensioning Intensity on Welding Distortion in Butt Joint with 304L Stainless Steel

作　　者：易斌[1] 周方明[2] 王江超[1] YI Bin;ZHOU Fangming;WANG Jiangchao(School of Naval Architecture and Ocean Engineering,Huazhong University of Science and Technology,Wuhan 430074;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003)

机构地区：[1]华中科技大学船舶与海洋工程学院,武汉430074 [2]江苏科技大学材料科学与工程学院,镇江212003

出　　处：《机械工程学报》2021年第6期60-69,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51609091)。

摘　　要：薄板焊接极易产生失稳变形,严重影响到薄板焊接结构件的生产效率和制造成本。以304L不锈钢薄板对接焊为研究对象,通过试验观察到马鞍形变形模式,并利用三维光学扫描仪测量焊接面外变形的大小。随后进行热-弹-塑性有限元分析再现焊接变形的过程,测量结果与基于大变形理论的数值计算结果基本吻合,而与基于小变形理论的计算结果差别很大,进一步验证失稳变形的产生。同时,在距离焊缝中心110 mm处施加随焊移动的辅助热源实现瞬态热拉伸来控制失稳变形,并研究了附加热源强度的影响。结果表明,瞬态热拉伸减小母材对焊缝处加热过程的压缩效应和冷却过程的拉伸效应,且附加加热区域会产生残余压缩塑性应变,降低了母材自身的纵向拘束度,从而降低焊接压应力和变形;并且附加加热区域最高温度达到195℃和273℃时,沿焊缝方向面外变形最大值分别减小了80%和72%,很大程度控制了焊接失稳变形。Welding induced buckling is common during thin plate welding and seriously affects the production efficiency and manufacturing cost of thin plate welding structures. 304 L stainless steel thin plate butt joints are taken as the research object. The pattern of saddle shape is observed through experiments, and the magnitude of out-of-plane deformation is measured using a three-dimensional optical scanning system. Subsequently, a thermo-elasto-plastic(TEP) finite element analysis is carried out to represent the process of welding distortion. The numerical predicted results based on large deformation theory are in good agreement with the measured data, and are different from the results based on small deformation theory, which verifies the occurrence of welding induced buckling. Meanwhile, in order to achieve transient thermal tensioning, two symmetrical additional heat sources moving synchronously with welding arc are applied to the region, which is away from welding line with the distance of 110 mm. In addition, the influence of the intensity of the additional heat source is studied. The results show that transient thermal tensioning decreases the compressive force during heating process and the tensile force during cooling process in the weld from base material, which will reduce the longitudinal self-constraints of the base material as well as reducing welding induced buckling. When the maximum temperature of the additional heating area reaches 195 ℃ and 273 ℃, the maximal deflection of points along the weld is decreased by 80% and 72%, respectively, and the welding induced buckling is almost controlled.

关 键 词：瞬态热拉伸 薄板焊接 焊接失稳变形 热-弹-塑性分析 附加热源 

分 类 号：TG404[金属学及工艺—焊接]