焊接修复对6082-T6铝合金焊接接头组织性能的影响  

Influence of welding repair on the microstructure and properties of 6082-T6 aluminum alloy welded joint

作　　者：闫占奇 王洪潇 王大臣 陆冠含 高雅 刘杰 YAN Zhanqi;WANG Hongxiao;WANG Dachen;LU Guanhan;GAO Ya;LIU Jie(CRRC Changchun Railway Vehicles Co.,Ltd.,Changchun,Jilin 130062,China;School of Mechanical and Electrical Engineering,Changchun Institute of Technology,Changchun,Jilin 130012,China)

机构地区：[1]中车长春轨道客车股份有限公司,吉林长春130062 [2]长春工程学院机电工程学院,吉林长春130012

出　　处：《轨道交通材料》2025年第2期37-41,共5页Materials for Rail Transportation System

摘　　要：采用熔化极氩弧焊(MIG)对10mm厚6082-T6铝合金板材分别进行3次及5次焊接修复,并对焊接修复后的接头组织及力学性能进行对比研究。结果表明:焊接接头修复次数对焊接接头的显微组织及弯曲性能影响不明显;3次焊接修复接头抗拉强度对比未焊接修复试样下降了近13%,5次焊接修复试样的抗拉强度未呈现进一步下降的趋势,基本与3次焊接修复抗拉强度一致。随着焊修次数的增加,接头抗拉强度的稳定性呈下降趋势;接头显微硬度值随焊接修复次数的增加而降低,未焊接修复、3次焊接修复及5次焊接修复试样的最低显微硬度值分别为73HV、61HV、60HV;在室温轴向抗拉疲劳试验条件下,5次焊接修复试样在1000万次循环加载的条件下中值疲劳强度为90.5MPa,相比未焊修试样下降了10%,分析断口可知,焊缝中的气孔边缘为疲劳起裂位置。A 10 mm thick 6082-T6 aluminum alloy plate is repaired by Metal Inert Gas Arc Welding(MIG)for three times and five times respectively,and the microstructure and mechanical properties of the welded joint after welding repair are compared and studied.The results indicate that the number of repair operation on the welded joints has no significant effect on the microstructure and bending properties of the welded joints;After 3 welding repairs,the tensile strength of the joint decreased by nearly 13%compared to the sam⁃ple without welding repairs.The tensile strength of the joint after 5 welding repairs doesn’t show a further downward trend,and is roughly the same as that of the joint after 3 welding repairs.As the number of welding repair increases,the stability of the tensile strength of the joint shows a declining curve;The microhardness of the joint decreases with the increase of welding repair times.The lowest microhardness of the joints with no welding repair,3 welding repairs and 5 welding repairs are 73 HV,61 HV,and 60 HV,re⁃spectively;Under the condition of axial tensile fatigue test at room temperature,the median fatigue strength of the specimen after 5 welding repairs under 10 million cycles of loading is 90.5 MPa,which is 10%lower than that of the specimen without welding repairs.Analysis of the fracture surface shows that the edge of the pore in the weld is the source where the fatigue crack starts.

关 键 词：6082-T6铝合金 MIG 焊接修复 轨道车辆 疲劳性能 

分 类 号：U270.64[机械工程—车辆工程] TG444.74[交通运输工程—载运工具运用工程]