• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2018, Vol. 54 ›› Issue (2): 55-61.doi: 10.3901/JME.2018.02.055

• 特邀专栏:焊接过程测控与数值模拟 • 上一篇    下一篇

低电流TIG电弧辅助MIG高速焊咬边缺陷抑制机理及措施的研究

陈姬1, 魏建华1, 周倩2, 武传松1   

  1. 1. 山东大学材料液固结构演变与加工教育部重点实验室 济南 250061;
    2. 山东劳动职业技术学院 济南 250022
  • 收稿日期:2017-05-27 修回日期:2017-07-19 出版日期:2018-01-20 发布日期:2018-01-20
  • 通讯作者: 陈姬(通信作者),男,1982年出生,博士,副教授。主要研究方向为焊接过程检测及数值模拟。E-mail:chenji@sdu.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(51305235)。

Suppression Mechanism of Low Current Auxiliary TIG Arc on High Speed TIG-MIG Hybrid Welding and Process Optimization

CHEN Ji1, WEI Jianhua1, ZHOU Qian2, WU Chuansong1   

  1. 1. Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education, Shandong University, Jinan 250061;
    2. Shandong Labor Vocational and Technical College, Jinan 250022
  • Received:2017-05-27 Revised:2017-07-19 Online:2018-01-20 Published:2018-01-20

摘要: 基于温度场、流场、熔滴过渡以及电弧形态检测,开展低电流钨极氩弧焊(Tungsten inert gas welding,TIG)辅助熔化极惰性气体保护(Metal inert gas welding,MIG)高速焊工艺试验。从传热、传质以及受力等角度分析低电流TIG辅助电弧对高速MIG咬边缺陷的抑制机理,并分析各工艺参数对最终焊缝成形的影响。相比常规MIG高速焊,低电流TIG辅助电弧能有效降低MIG高速焊前部熔池边缘的温度梯度,延长熔池存在时间,促进液态金属向焊缝边缘填充。电弧力和熔滴冲击力是影响高速焊咬边缺陷的主要作用力,低电流TIG辅助电弧对MIG熔滴冲击力改变较小,但两电弧耦合后,电弧静、动压力明显降低,可有效地抑制MIG高速焊中咬边缺陷的产生。此外,正交工艺试验显示,丝-极间距和焊枪倾角是影响复合焊工艺的重要参数,而钨极距工件距离和TIG焊接电流则对咬边缺陷的影响较小,通过对丝-极间距和焊枪倾角的调节能快速实现该复合焊工艺参数的优化,抑制咬边缺陷。

关键词: TIG-MIG, 工艺优化, 咬边缺陷, 抑制机理

Abstract: The low current auxiliary TIG arc assisted high speed MIG process is carried out to analyze the suppression mechanism of undercut defect from the aspects of heat transfer, mass transfer and force field. The influence of the welding parameters on undercut defect is also analyzed. The low current auxiliary TIG arc can effectively reduce the temperature gradient around the edge of the weld pool during high speed MIG, which prolongs the existence time of the molten pool and promotes the filler metal to the edge of the weld to prevent undercut defect. The arc force and the droplet impact play major roles in the formation of the undercut defect. The auxiliary of low current TIG presents slight influence on MIG droplet, however, it can reduce the arc static and dynamic pressure obviously to mitigate or even inhibit undercut defect during the high-speed welding process. The orthogonal test shows that the inclination angle of welding torch, and the spacing of wire-pole are the important parameters affecting the formation of undercut defect compared with TIG current and tungsten distance workpiece distance. Optimizing torch angle and wire-pole spacing is a fast and economical way to improve low current auxiliary TIG-MIG hybrid welding to suppress undercut defect.

Key words: process optimization, suppression mechanism, TIG-MIG, undercut defect

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