Comparative study on welding procedure and performance of 8 mm thick TC4 titanium alloy with TIG and MIG

8mm厚TC4钛合金TIG、MIG焊接工艺及性能对比研究 Comparative study on welding procedure and performance of 8 mm thick TC4 titanium alloy with TIG and MIG 牟刚 MOU Gang 1 first-author 华学明 HUA Xueming 1 徐小波 XU Xiaobo 2 王欢 WANG Huan 1 李芳 LI Fang 1 王敏 WANG Min 1 上海交通大学材料科学与工程学院焊接工程研究所激光制造实验室 上海交通大学材料科学与工程学院焊接工程研究所激光制造实验室 Welding Engineering Institute,College of Materials Science and Engineering,Shanghai Jiaotong University Welding Engineering Institute,College of Materials Science and Engineering,Shanghai Jiaotong University 沪东中华造船(集团)有限公司 沪东中华造船(集团)有限公司 Hudong-zhonghua Shipbuilding (Group) Co.,Ltd. Hudong-zhonghua Shipbuilding (Group) Co.,Ltd. 以8 mm TC4钛合金厚板为实验材料,采用手工钨极气体保护焊(TIG)和熔化极气体保护焊(MIG)研究了各自实验条件下的焊缝成形、微观组织、力学性能和拉伸断口的异同。结果表明,TIG、MIG焊焊缝均成形美观,但MIG焊焊接速度更快;母材为α+β双相组织,MIG焊热影响区晶粒比TIG焊更均匀;二者焊缝均由粗大柱状晶组成,组织均为α’马氏体+β相;手工TIG焊接头强度系数达到97.3%,摆动电弧MIG焊接头强度系数为93.9%,摆动电弧MIG焊强度低的原因在于焊缝中存在冶金型气孔缺陷。 In this paper,an 8 mm thick TC4 titanium alloy thick plate was used as the experimental material. Under the test conditions of two kinds of welding methods:manual tungsten inert gas arc（TIG） welding and metal inert-gas arc（MIG）welding,the similarities and differences of formation of weld,microstructure,mechanical properties and tensile fractures were studied. The results show that both TIG and MIG have good formation of weld,but the MIG welding speed is faster;the base metal is α+β dual phase microstruc-ture,the grain of the MIG welding heat affected zone is more uniform than that of TIG welding. Both welds are composed of thick columnar crystals,and the microstructure is α’ martensite +β phase. The strength coefficient of manual TIG welded joint is 97.3%,and the strength coefficient of the oscillating arc MIG welded joint is 93.9%. The reason for the low strength of the oscillating arc MIG welding is the existence of blowhole defects in the weld. 钛合金 中厚板 TIG焊 摆动电弧MIG焊 微观组织 titanium alloy medium thick plate TIG welding oscillating arc MIG welding microstructure TG444.74 国家重点研发计划(2016YFB0301205) 2022-03-08 4 50