13MnNiMo54/20MnMo异种金属埋弧焊接头性能研究

摘要

采用埋弧焊方法对板厚为106mm的13MnNiMo54/20MnMo进行了异种金属多层多道焊,在检验合格的焊件上截取并制备试样.通过对焊接接头金属进行组织观察、高温拉伸试验以及显微硬度测试研究了异种金属焊接接头的性能.结果表明:中间层焊缝金属组织以细小的块状铁素体为主,表层焊缝金属组织主要为粗大的先共析铁素体和针状铁素体;20MnM.侧HAZ粗晶区是焊接接头的薄弱部位;表层焊接接头金属硬度高于中间层接头金属的硬度,20MnMo侧HAZ粗晶区金属的硬度值最高.%The welding of 13MnNiMo54/20MnMo dissimilar metal joints is performed by multilayer and muhipass submerged arc welding process. The specimens are cut and prepared from qualified weldments. The microstructure of the joint metal is observed,high-temperature tensile test is conducted and the metal mierohardness of the dissimilar welded joints is measured. The results show that the microstructures of the joint middle layer microstructure is mainly fine blocky ferrite while the microstructure of the joint surface layer metal is coarse pre-eutectoid ferrite and acicular ferrite. The coarse grain HAZ is the weak location of the welded joint. The hardness value of the joint surface layer metal is higher than that of joint middle layer metal. The maximum hardness value appears in the coarse grain HAZ adjacent to the side of the base metal 20MnMo.