Mg元素和表层晶粒对3A21铝合金CAB焊接性能的影响  

Effect of Mg and Surface Grain on CAB Weldability of 3A21 Aluminum Alloy

作　　者：朱单单 杨炳元 刘享新 ZHU Dandan;YANG Bingyuan;LIU Xiangxin(Guizhou Yonghong Heat Transfer&Cooling Technology Co.,Ltd.,Qiannan 550600,Guizhou,China)

机构地区：[1]贵州永红换热冷却技术有限公司,贵州黔南州550600

出　　处：《焊管》2024年第7期32-38,共7页Welded Pipe and Tube

摘　　要：为了研究Mg含量及表层晶粒对3A21铝合金可控气氛保护焊(CAB)焊接性能的影响,通过含氟化物钎剂的CAB工艺对不同Mg含量及晶粒分布的铝合金进行钎焊,采用气密测试台、爆破试验台、金相显微镜、场发射扫描电子显微镜(SEM)观察3A21铝合金钎焊缝的微观形貌并进行力学性能分析。结果表明,Mg元素在CAB焊接过程中与钎剂中的F元素生成高熔点化合物,消耗钎剂的有效成分并形成夹渣缺陷。零件表层均匀分布的1级晶粒度的晶粒层在钎焊过程中稳定存在且可促使钎焊形成良好的钎焊缝。当Mg含量低于0.015%、表层分布均匀环状晶粒时,3A21铝合金具有良好的CAB焊接性能。In order to study the effects of Mg content and surface grains on the controlled atmosphere brazing(CAB)weldability of 3A21 aluminum alloy,CAB welding process containing fluoride flux was used to braze aluminum alloy with different Mg content and grain distribution,and the microstructure and mechanical properties of 3A21 aluminum alloy brazed weld were analyzed by airtight test bench,blasting test bench,metallographic microscope and field emission scanning electron microscope(SEM).The results show that Mg elements form high melting point compounds with F elements in the flux during CAB welding,consume the active components of the flux and form slag inclusion defects.The grain layer of grade 1 grain size uniformly distributed on the surface of the part is stable in the process of brazing and can promote the formation of the good brazed weld.When Mg content is less than 0.015%and there are uniformly distributed circular grains on the surface,3A21 aluminum alloy has good CAB weldability with fluoride flux.

关 键 词：3A21铝合金 CAB焊接 钎焊缝 Mg含量 晶粒尺寸 

分 类 号：TG406[金属学及工艺—焊接]