摘要:
本文以 SAl 5183 新型号船用铝合金焊丝为研究对象，采用TIG/MIG焊接技术对5083-H116铝合金分别进行立向上焊、仰焊、平焊以研究该型号焊丝焊接的冶金性和可靠性。研究内容包括熔敷金属性能测试、化学成分分析、焊接接头力学性能测试、微观组织分析等。结果显示，该焊丝熔敷金属抗拉强度达到291 MPa、延伸率30%，其化学成分也均满足CCS材料与焊接规范要求。接头拉伸测试表明MIG焊接接头的抗拉强度略高于TIG焊接接头，相同焊接技术下立向上焊、仰焊、平焊三种焊接接头力学性能接近且抗拉强度均达到母材抗拉强度的90%。显微组织检测结果显示，在不同焊接工艺下焊缝区均观察到了白色弥散相Al6(Fe，Mn)化合物，其中，采用MIG立向上焊和平焊焊接工艺时，焊接接头内析出相体积尺寸相对更大，弥散强化效果更好；此外，焊缝区域也观察到了Mg元素固溶强化效果，其中，采用MIG立向上焊、TIG立向上焊和TIG仰焊焊接工艺时，接头内Mg元素分布更加均匀，固溶强化效果更好；上述两种强化效果保证了焊接接头良好的抗拉强度。
Abstract:
The study focuses on the newly developed SAl 5183 marine aluminum alloy welding wire, with the base material selected as 5083-H116 aluminum alloy. The TIG/MIG welding techniques were employed to conduct vertical up, overhead, and flat welding to investigate the metallurgical properties and reliability of this welding wire. The research includes tests on the properties of the deposited metal, chemical composition analysis, mechanical performance testing of the welded joints, and microstructural analysis. The results indicate that the tensile strength of the deposited metal reaches 291 MPa with an elongation of 30%, and its chemical composition meets the requirements of CCS material and welding specifications. Tensile tests on the joints show that the tensile strength of the MIG welded joints is slightly higher than that of the TIG welded joints, while the mechanical properties of the vertical up, overhead, and flat welded joints under the same welding technique are similar, with tensile strengths reaching 90% of the base material's tensile strength. Microstructural examination reveals the presence of white dispersed phase Al6(Fe, Mn) compounds in the weld zone under different welding processes. Notably, when using MIG flat welding and vertical up welding processes, the size of precipitate phase in the welded joints is relatively larger, resulting in better dispersion strengthening effects. Additionally, the weld zone exhibits the solid solution strengthening effect of Mg elements, with a more uniform distribution of Mg in the joints produced by MIG vertical up welding, TIG vertical up welding, and TIG overhead welding, leading to enhanced solid solution strengthening effects. These two strengthening effects ensure the welded joints possess good tensile strength.
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