大电流GMAW焊接飞溅和烟尘的形态及相结构分析  

Morphology and Phase Structure Analysis of Spatter and Fume in High Current GMAW Welding

作　　者：樊丁[1,2] 杨文艳 肖磊[1] FAN Ding;YANG Wenyan;XIAO Lei(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050;State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《材料导报》2019年第16期2729-2733,共5页Materials Reports

基　　金：国家自然科学基金项目(51775256);甘肃省基础研究创新群体计划项目(17JR5RA107);甘肃省高校协同创新团队项目(2017C-07)~~

摘　　要：在熔化极气体保护焊(Gas metal arc welding,GMAW)过程中,当熔滴过渡转变为旋转射流过渡时,电弧不稳,焊缝成形变差。在Q235低碳钢上开展工艺试验,探究焊接过程中产生的飞溅和烟尘的形态及相结构。结果表明,高温熔融的金属被甩出雾化,雾滴在飞行过程中球化并快速凝固,飞溅颗粒表面具有特殊形貌,其成分以氧化物为主。电弧燃烧时,焊丝端部形成电流密度很高的斑点,斑点处温度很高,随着焊接电流的增大,金属蒸发量增加。金属蒸发带走了焊丝中大部分的Si、Mn等合金元素,而Si和Mn均是有效脱氧的元素。因此,金属蒸发带走了合金元素,影响O含量,进而影响焊缝性能。烟尘粒径与熔滴过渡方式有关,其粒度范围可达10^-1~10^2μm,分布概率较大的是10~60μm的粒子,它能通过人体上呼吸道进入肺部,对人体呼吸系统、神经系统等造成损伤。In the process of gas metal arc welding(GMAW),the arc is unstable and the formation of the weld becomes worse when the droplet transfer is transformed into a rotating jet.A process tests were carried out on Q235 low carbon steel to explore the morphology and phase structure of the spatter and fume generated during welding.The results showed that the molten metal at high temperature is thrown out and atomized,and the droplets were spheroidized and solidified rapidly during the flight.The surface of the spattered particles exhibited a special appearance,and the particles were mainly composed of oxide.When the arc burned,the spot with high current density formed at the end of the welding wire,and the temperature at the spot was quite high.With the increase of welding current,the amount of metal evaporation increased.Metal evaporation takes away most of the Si,Mn and other alloy elements in the welding wire.While Si and Mn are all effective deoxidizing elements,therefore,the alloying elements was removed by metal evaporation,which affected the content of O,and further exerted negative effect on the weld performance.The particle size of smoke and dust to the mode of droplet transfer,ranging from 10^-1μm to 10^2μm.The majority of particle possessed the size of 10μm to 60μm,which could enter the lungs through the upper respiratory tract,and would do harm to the respiratory system and the nervous system of the human body.

关 键 词：旋转射流过渡 高速GMAW 飞溅颗粒形态 焊接烟尘 

分 类 号：TG442[金属学及工艺—焊接]