6N01铝合金水冷MIG焊接头组织和性能  

Microstructure and mechanical properties of water-cooled MIG welded joints of 6N01 aluminium alloy

作　　者：梁志敏[1] 石康柠 李伟坡[1] 曹益[1] 路浩 LIANG Zhimin;SHI Kangning;LI Weipo;CAO Yi;LU Hao(School of Material Science and Technology,Hebei University of Science and Technology,Shijiazhuang 050018,China;CRRC Qingdao Sifang Co.,Ltd,Qingdao 266111,China)

机构地区：[1]河北科技大学材料科学与工程学院,石家庄050018 [2]中车青岛四方机车车辆股份有限公司,青岛266111

出　　处：《焊接学报》2018年第9期25-30,130,共7页Transactions of The China Welding Institution

基　　金：十二五国家科技支撑计划高速列车综合节能关键技术与集成应用项目(2013BAG24B02);国家自然科学基金资助项目(51205106);四方股份工艺开发资助项目

摘　　要：针对6N01铝合金熔化焊接头软化问题,研究了水冷对MIG焊接头组织和性能的影响,并与自然冷却条件下接头进行对比.金相试验结果表明,水冷使填充和盖面焊道部分熔化区变窄,焊缝近熔合线的柱状晶区变宽,焊缝内部等轴晶细化;显微硬度试验结果表明水冷条件下接头软化区范围明显变窄且硬度提高;软化区TEM观察显示水冷减少了β'析出相长大;水冷还提高了MIG焊接接头屈服强度和抗拉强度.结果表明,水冷能优化6N01铝合金MIG接头组织并提高力学性能.In order to alleviate the softening problem of 6N01 aluminum alloy during fusion welding,the microstructure and mechanical properties of MIG welded joints with water accelerated cooling were studied and compared with the joints under natural cooling conditions.The results of metallographic experiments showed that the partially melted zones of filling pass and cover pass were narrowed by water cooling.The columnar grain regions of the weld near the fusion line were widened and the equiaxed grains in the weld were refined.Microhardness test results showed that the softening zone of the joint was significantly narrowed and the hardness increased under water cooling conditions.The TEM morphology of the softened zone showed that the sizes ofβ'precipitation were also reduced.The yield strengths and tensile strengths of MIG welded joints were also improved by water cooling.The experimental results confirmed that water cooling can optimize the microstructure and improve the mechanical properties of MIG welded 6N01 aluminum alloy joints.

关 键 词：6N01铝合金 MIG焊 水冷 显微组织 力学性能 

分 类 号：TG444[金属学及工艺—焊接]