微合金元素改性对AlMg4.3Mn0.6Cr0.12-H321合金TIG焊接头组织及性能影响  

Effect of micro-alloying elements modification on the microstructure and properties of TIG welded joints of AlMg4.3Mn0.6Cr0.12-H321 alloy

作　　者：谷宁杰 吴浩 毛晓东 宋小雨 邹立颖 董学光 史晓成 GU Ningjie;WU Hao;MAO Xiaodong;SONG Xiaoyu;ZOU Liying;DONG Xueguang;SHI Xiaocheng(Chinalco Material Application Research Institute Co.,LTD.td,Beijing,102209,China)

机构地区：[1]中铝材料应用研究院有限公司,北京102209

出　　处：《焊接学报》2025年第3期127-136,共10页Transactions of The China Welding Institution

摘　　要：采用5B71合金焊丝对添加不同微合金成分的AlMg4.3Mn0.6Cr0.12-H321合金进行TIG焊接试验,系统研究微合金元素Zr,Er,Sc对焊接接头的微观组织、显微硬度和力学性能的影响.结果表明,AlMg4.3Mn0.6Cr0.12-H321基材为变形条带组织,TIG焊缝区为等轴凝固组织.微量元素Zr,Er,Sc的添加可在基材中形成纳米析出相,起钉扎位错,抑制合金再结晶的作用.相比单独添加Zr元素,复合添加Zr,Er和Zr,Sc元素能够更有效地抑制焊缝热影响区再结晶行为,降低焊接过程基材软化.5组接头显微硬度均沿焊缝中心呈W形对称分布,在热影响区达到最低,相应地,力学拉伸试样均断在热影响区,随着微合金元素种类及添加量的增加,接头强度逐渐提高;当Er元素提高到0.35%时,焊缝抗拉强度达到274MPa,焊接系数为83.3%;复合添加Zr,Sc元素的5号试样接头抗拉强度最大为293MPa,焊接系数为89.7%.创新点:(1)提出通过微合金元素的添加调控铝合金在焊接过程中的再结晶行为.(2)揭示了Zr,Er,Sc微合金元素对AlMg4.3Mn0.6Cr0.12-H321TIG焊接头组织性能的影响机理.Tungsten inert gas(TIG)welding tests were conducted on AlMg4.3Mn0.6Cr0.12-H321 alloy with varied micro-alloying elements using ER5B71 filler wire.The influence of micro-alloying elements Zr,Er,and Sc on the microstructure,microhardness,and mechanical properties of welded joints was systematically investigated.The results indicate that the base material exhibits a deformed band structure,while the weld zone exhibits an equiaxed solidification microstructure.The addition of micro-alloying elements Zr,Er,and Sc forms nanoscale precipitates in the matrix,which effectively pin dislocations and inhibit alloy recrystallization.Compared with adding Zr element alone,adding Zr,Er,or Zr,Sc elements can more effectively suppress recrystallization behavior in the weld heat-affected zone(HAZ)and reduce base material softening during welding.All five groups of joints show W-shaped symmetrical microhardness distributions along the weld centerline,reaching minimum values in the HAZ.Correspondingly,tensile samples all fractured in the HAZ.The butt joint strength gradually increases with the variety and content of micro-alloying elements.When the Er content is 0.35%,the samples achieve the tensile strength of 274 MPa with a joint efficiency of 83.3%.The Zr-Sc co-doped samples(#5)achieve the maximum tensile strength of 293 MPa,corresponding to a joint efficiency of 89.7%.Highlights:(1)It was proposed to regulate the recrystallization behavior of aluminum alloy during welding process by adding micro-alloying elements.

关 键 词：AlMg4.3Mn0.6Cr0.12合金 TIG焊接 再结晶行为 焊接强度 

分 类 号：TG457.1[金属学及工艺—焊接]