摘要
针对钛合金薄板激光焊接残余应力与焊接变形大的问题,提出了液氮冷却激光焊接方法,将液氮冷却氩气作为冷却介质作用于试件表面。开展了TC4钛合金锁底结构液氮冷却激光焊接实验,分析了不同冷却条件下TC4钛合金激光焊接接头的微观组织、残余应力与焊接变形。结果表明,相较于自然冷却的激光焊接接头,液氮冷却激光焊接接头热影响区宽度变窄,焊缝中部宽度增大63.7%,下熔宽增大70.5%,焊缝组织更为均匀,焊后变形显著减小,整体变形量降低约5.2%。这是由于液氮冷却熔池后方处于高温的金属急剧冷却,很大程度上补偿了已产生的压缩塑性应变,使得焊接变形减小。
Focusing on the problem of large residual stress and welding deformation in laser welding with titanium alloy thin-walled structures,a laser welding method with liquid nitrogen-assisted cooling was proposed for the control of welding deformation,in which liquid nitrogen cooled argon was used as the cooling medium on the surface of the specimen.The laser welding experiment of TC4 titanium alloy lock bottom structure with liquid nitrogen cooling was carried out.The microstructure,residual stress and welding deformation of TC4 titanium alloy laser welded joint under different cooling conditions were analyzed.The results show that compared with the laser welded joint with natural cooling,the width of heat affected zone of liquid nitrogen cooled laser welded joint was narrower,the middle width of weld joint was increased by 63.7%,the down melting width was increased by 70.5%,the weld structure was more uniform,the weld deformation was significantly reduced,and the overall deformation was reduced by about 5.2%.Due to the metal at high temperature behind the molten pool cooled by liquid nitrogen cools rapidly,which compensates the compressive plastic strain to a great extent and reduces the welding deformation.
作者
叶泽涛
李悦
马龙飞
占小红
王建峰
庄明祥
YE Zetao;LI Yue;MA Longfei;ZHAN Xiaohong;WANG Jianfeng;ZHUANG Mingxiang(College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China;Avic Xi'an Aircraft Industry Group Company Ltd,Xi'an 710089,China)
出处
《电焊机》
2023年第7期60-66,共7页
Electric Welding Machine
基金
国防基础科研项目(JCKY2021605B015)。
关键词
TC4钛合金
锁底结构
激光焊接
液氮冷却
残余应力
焊接变形
TC4 titanium alloy
lock bottom structure
laser welding
liquid nitrogen-assisted cooling
residual stress
welding deformation
