【摘要】 通过采用MAG熔焊方法并选择合适的高强钢焊丝，进行1 700 MPa级超高强钢和Q550D高强钢板的异种焊接，得出了最佳焊接工艺参数，并对焊接机头进行了组织及力学性能试验。结果表明，异种焊缝组织主要由羽毛状的下贝氏体组成，在焊态焊缝组织中没有发现马氏体组织；而在1 700 MPa级超高强钢的熔合线附近一侧，发现大量沿熔合线垂直生长的板条马氏体组织；力学性能测试表明，焊接接头性能满足生产使用要求，为超高强钢的应用提供了试验依据。更多还原

【Abstract】 By using MAG fusion welding method and selecting appropriate high-strength steel welding wires, the optimal welding process parameters were obtained for dissimilar welding of 1 700 MPa grade UHSS(ultra-high strength steel) and Q550D high-strength steel plate. The microstructure and mechanical properties of the welding head were tested. The results show that the microstructure of dissimilar welds is mainly composed of feathery lower bainite, and no martensite structure was found in the welded weld microstructure; On the side near the fusion line of 1 700 MPa grade ultra-high strength steel, a large amount of lath martensite was found growing vertically along the fusion line; Mechanical performance tests have shown that the performance of welded joints meets production and usage requirements, providing experimental basis for the application of ultra-high strength steel.更多还原