稀土元素对新型Al-Mg合金焊接接头组织和性能的影响  

Effect of rare earth elements on microstructure and mechanical properties of new Al-Mg alloy welded joints

作　　者：任思蒙 杨阳 吴浩 路丽英[2] 赵丕植 宋小雨 Ren Simeng;Yang Yang;Wu Hao;Lu Liying;Zhao Pizhi;Song Xiaoyu(Chinalco Materials Application Research Institute Co.,Ltd.,Beijing 102209,China;Northeast Light Alloy Co.,Ltd.,Harbin 150001,China)

机构地区：[1]中铝材料应用研究院有限公司,北京102209 [2]东北轻合金有限责任公司,哈尔滨150001

出　　处：《焊接》2022年第12期55-61,共7页Welding & Joining

摘　　要：研究了Sc,Zr元素对新型Al-Mg合金焊接接头组织和性能的影响。建立了MIG电弧二维数值分析模型,模拟出电弧温度场的分布情况,电弧最高温度超过20000 K,且温度分布存在较大的温度梯度,说明高温电弧对合金有益元素有一定的烧损作用。采用合金元素不同的焊丝ER5356,ER5B06和ER5B71作为填充材料,对2 mm厚新型Al-Mg合金进行MIG焊接试验,研究高Mg焊丝添加不同稀土元素对焊接性能及组织的影响。结果表明,使用3种焊丝均可获得性能优良的焊接接头,使用ER5B06焊丝的接头力学性能得到一定提升,但焊缝晶粒细化效果不明显;使用复合添加Sc,Zr微量元素的ER5B71焊丝,接头晶粒能够有效细化,力学性能进一步得到提升。3种焊丝中,采用ER5B71焊丝的焊接接头强度最高,焊接系数为83%,焊接接头中起到细化晶粒作用的析出相以Al_(3)(Sc,Zr)为主。同时,无论采用哪种焊丝,焊接热影响区未发生明细的晶粒粗化,说明在母材中加入一定的Sc,Zr微量元素,可提升合金材料抗软化能力,有效抑制热影响区再结晶行为。Effects of Sc and Zr elements on microstructure and mechanical properties of new Al-Mg alloy welded joints were studied.A two-dimensional numerical analysis model of MIG arc was established to simulate distribution of arc temperature field.The maximum temperature of arc exceeded 20000 K and temperature distribution had a large temperature gradient,which showed that high temperature arc had a certain effect on burning loss of beneficial elements of the alloy.ER5356,ER5B06 and ER5B71 welding wires with different alloying elements were used as filler materials,MIG welding experiments were carried out on new Al-Mg alloy with 2 mm thickness to study effects of high Mg welding wires with adding different rare earth elements on welding performance and microstructure.The results showed that welded joints with excellent mechanical properties could be obtained by three kinds of welding wires.Mechanical properties of welded joints were improved to a certain extent by ER5B06 welding wire,but grain refinement effect of weld was not obvious.Grains of welded joints could be effectively refined and mechanical properties were further improved by ER5B71 welding wire with compound addition of Sc and Zr trace elements.Among the three kinds of welding wires,welded joints with ER5B71 welding wire had the highest strength,and welding coefficient was 83%.The precipitations in welded joints that played the role of grain refinement were mainly Al_(3)(Sc,Zr).At the same time,no matter any kind of welding wire was used,no obvious grain coarsening occurred in welding heat affected zone,which declared that adding Sc and Zr trace elements to base metal could improve softening resistance of the material and effectively inhibit recrystallization behavior of heat-affected zone.

关 键 词：新型Al-Mg合金 MIG 焊丝 组织 力学性能 

分 类 号：TG456[金属学及工艺—焊接]