基于水雾在线冷却的钛合金激光焊接应力变形研究  

Experimental Study on Laser Welding Stress and Deformation of Titanium Alloy Based on Synchronous Water Mist Cooling

作　　者：高庆生 章文亮 庄明祥 叶泽涛 刘永强 占小红[2] GAO Qingsheng;ZHANG Wenliang;ZHUANG Mingxiang;YE Zetao;LIU Yongqiang;ZHAN Xiaohong(AVIC Xi'an Aircraft Industry(Group)Company Ltd.,Xi'an 710089,China;School of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)

机构地区：[1]中航西安飞机工业集团股份有限公司,陕西西安710089 [2]南京航空航天大学材料科学与技术学院,江苏南京211106

出　　处：《电焊机》2024年第6期80-86,共7页Electric Welding Machine

摘　　要：为解决TC4钛合金薄板激光焊接后因残余应力引起的变形问题,选用500 mm×50 mm×1.2 mm规格的TC4钛合金薄板作为研究对象,通过激光焊接并应用水雾在线冷却法进行同步冷却。保持激光功率、焊接速度、离焦量等焊接工艺参数一致,仅改变水雾压力,以研究不同冷却条件下的应力变形控制效果。结果表明,在水雾压力为0.4 MPa、激光功率800 W、焊接速度1.3 m/min、离焦量0 mm的条件下,与自然冷却相比,焊后残余应力降低了29%,最大纵向挠曲变形量减少17.6%;水雾冷却下的焊缝组织尺寸更细小,分布更规整有序。试验证明,水雾在线冷却法能有效改善TC4钛合金薄板激光焊接后的残余应力和变形问题,还可以促进马氏体相变,使焊缝的网篮状组织更加规整有序,从而提升接头的力学性能。In this paper,the TC4 titanium alloy sheet with a specification of 500mm×50mm×1.2mm is taken as the research object.In order to solve the problem of deformation caused by residual stress after laser welding,a Synchronous water mist cooling method is used to synchronously cool the rear of the heat source during the welding process.The effectiveness of this method was verified by measuring and comparing the deformation and stress levels before and after welding.The test shows that the deformation and residual stress of the specimen obtained by synchronous water mist cooling are greatly improved compared with those obtained by natural cooling under the same welding process parameters.Compared with the test results under different water mist pressures,when the water mist pressure is 0.4MPa,the laser power is 800W,the welding speed is 1.3m/min,and the defocus amount is 0mm,the residual stress after welding can be reduced by 29%compared with Free cooling,and the maximum longitudinal deflection can be reduced by 17.6%.Moreover,by observing the microstructure of the weld,it can be seen that the size of the weld net basket structure under the synchronous water mist cooling is smaller and the distribution is more orderly,indicating that the water mist cooling has a certain refining effect on the microstructure and can improve the mechanical properties of the welded joint.

关 键 词：激光焊接 水雾冷却 焊接变形 残余应力 TC4钛合金 

分 类 号：TG456.7[金属学及工艺—焊接] TG404