2A12铝合金TIG焊接接头显微组织及性能
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摘要
采用ER4043焊丝对2A12铝合金进行钨极惰性气体保护焊(TIG焊),通过显微组织观察(OM和SEM)、拉伸性能及硬度检测,对焊接接头显微组织及性能进行了研究。结果表明:2A12焊接接头热影响区晶粒大小不一。焊缝区显微组织为典型的铸态枝晶,呈现网状分布特征,枝晶组织的生长具有方向性。焊接接头抗拉强度平均值为281.3MPa,为母材的67.9%。母材断口呈韧窝型延性断裂,焊缝断口呈脆韧型混合断裂。焊缝中心硬度较低,其值为86 HB。热影响区是焊接件的最薄弱环节,硬度最低,仅为82 HB。275℃×12 h热处理对2A12焊接件的硬度影响很小。
Tungsten inert gas welding(TIG welding) of 2A12 aluminum alloy was carried out by using ER4043 welding wire. The microstructure and properties were studied by microstructure observation, tensile and hardness test. The results shows that the grain size of the heat affected zone of 2A12 welded joint is different. The microstructure of the weld zone is typical as cast dendritic structure, which shows network distribution characteristic, and the growth of dendrite structure is directional. The average tensile strength of welded joint is 281 MPa, which is 67.9% of base metal. The fracture of the base metal is dimple ductile fracture, and the fracture of the weld is brittle and tough mixed fracture. The hardness of weld center is lower, the value reaches 86 HB. The HAZ is the weakest zone, the hardness is the lowest, the value is only 82 HB. The effect of 275℃×12 h heat treatment on the hardness is negligible.
Tungsten inert gas welding(TIG welding) of 2A12 aluminum alloy was carried out by using ER4043 welding wire. The microstructure and properties were studied by microstructure observation, tensile and hardness test. The results shows that the grain size of the heat affected zone of 2A12 welded joint is different. The microstructure of the weld zone is typical as cast dendritic structure, which shows network distribution characteristic, and the growth of dendrite structure is directional. The average tensile strength of welded joint is 281 MPa, which is 67.9% of base metal. The fracture of the base metal is dimple ductile fracture, and the fracture of the weld is brittle and tough mixed fracture. The hardness of weld center is lower, the value reaches 86 HB. The HAZ is the weakest zone, the hardness is the lowest, the value is only 82 HB. The effect of 275℃×12 h heat treatment on the hardness is negligible.
引文
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[8]王燕,魏晓红,胡宗智.LY12硬铝合金与TIG与A-TIG焊接接头组织和熔深的研究[J].新技术新工艺,2011(8):131-133.
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[11]彭云,许良红,田志凌,等.焊接热输入对高强铝合金接头组织和性能的影响[J].焊接学报,2008,29(2):17-21.
[2]陈建,张修智,吴忍耕.高强铝合金焊接接头SCC机理探讨究[J].焊接学报,1990,11(2):91-98.
[3]DevincentSM,DevletianJH,GedeonSA.Weldpropertiesofthe newly developed 2519-T87 aluminum armor alloy[J].Welding Journal,1988(3):33-43.
[4]高明霞,余红华.LC9CS铝合金焊缝的组织和强度及断裂形式[J].焊接学报,1998(12):58-62.
[5]李慧中,张新明,陈明安,等.2519铝合金焊接接头的组织与性能[J].中国有色金属学报,2004,14(6):956-960.
[6]殷春喜,黄军庆,熊震东,等.铝及铝合金TIG焊接特性[J].热加工工艺,2011,40(1):129-131.
[7]严军,高明,曾晓雁.激光-MIG复合焊接2A12铝合金工艺和接头性能[J].中国有色金属学报,2009,19(12):2112-2118.
[8]王燕,魏晓红,胡宗智.LY12硬铝合金与TIG与A-TIG焊接接头组织和熔深的研究[J].新技术新工艺,2011(8):131-133.
[9]严军,高明,曾晓雁.激光-MIG复合焊接2A12铝合金工艺和接头性能[J].中国有色金属学报,2009,19(12):2112-2118.
[10]国旭明,杨成刚,钱百年.高强Al-Cu合金脉冲MIG焊接工艺[J].焊接学报,2004,25(4):7-8.
[11]彭云,许良红,田志凌,等.焊接热输入对高强铝合金接头组织和性能的影响[J].焊接学报,2008,29(2):17-21.