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采用水蒸气等离子焊接技术对2A12铝合金材料进行焊接,采用4种缓冷工艺对其进行缓冷处理,并利用电子万能试验机、奥林巴斯金相显微镜、X-350A型应力测定仪以及HVS-1000型数显显微硬度计对不同缓冷工艺处理后焊接试样的组织和性能进行分析和测定。结果表明:2A12铝合金焊接接头的最大抗拉强度为250 MPa。焊接接头包括基体、热影响区、熔合区及焊缝四个区,不同区域的焊缝组织和性能各不相同,其中热影响区由于受焊接热输入的影响出现了晶粒长大、显微硬度降低的现象。此外,经过固溶强化和人工时效处理后,焊接接头的残余应力值大大降低,抗拉强度和显微硬度都有一定的增加。
The water vapor plasma welding technology was used to weld 2A12 aluminum alloy. Four kinds of slow cooling techniques were used to slow down the cooling process. The electronic universal testing machine, Olympus microscope, X-350A stress tester and HVS -1000 digital microhardness tester for different slow cooling process after welding the sample structure and performance analysis and determination. The results show that the maximum tensile strength of 2A12 aluminum alloy welded joint is 250 MPa. The welded joint includes four zones of matrix, heat-affected zone, fusion zone and weld zone. The microstructure and properties of weld in different zones are different. The heat-affected zone appears grain growth due to the influence of welding heat input, The phenomenon of reduced hardness. In addition, after solid solution strengthening and artificial aging treatment, the residual stress value of welded joint is greatly reduced, and both the tensile strength and microhardness increase a little.