轨道交通铝合金型材激光−电弧复合焊工艺适应性

Adaptability of laser-arc hybrid welding process for aluminum alloy profile of rail transit

针对轨道交通3 mm铝合金型材,采用激光−电弧复合焊工艺方法,对生产过程中常出现的错边、装配间隙对焊缝质量的影响规律开展试验研究。结果表明,激光−电弧复合焊对轨道交通铝合金型材焊接的工况适应性较强;在试验条件下,装配间隙主要影响焊缝余高及接头抗拉强度;随着装配间隙的增大,焊缝余高降低直至出现下凹,接头抗拉强度有所降低;错边量增大,会导致焊缝表面飞溅变多,装配错边对焊缝气孔及接头抗拉强度等影响不明显;在试验条件下,0.5 mm装配间隙及错边以内,激光−电弧复合焊焊缝成形、气孔、接头金相组织和抗拉强度均满足生产需求。

Aiming at 3 mm aluminum alloy profiles of rail transit,laser-arc hybrid welding process was used to study influence of misalignment and assembly gap that often appeared in the production process on weld quality.The results showed that laser arc hybrid welding had stronger adaptability to welding conditions of aluminum alloy profiles in rail transit.Under the test conditions,assembly gap mainly affected reinforcement of weld and tensile strength of welded joints.With the increase of assembly gap,reinforcement of weld decreased until concave appeared,which reduced tensile strength of welded joints.Increase of misalignment would lead to more spatter on the surface of weld,while misalignment had no obvious effect on porosity of weld and tensile strength of welded joints.Under the test conditions,formation of weld,porosity,metallographic microstructure and tensile strength of welded joints by laser-arc hybrid welding met production requirements within 0.5 mm assembly gap and misalignment.