基于原位拉伸的CrMoV钢焊接接头局部力学性能研究

采用微拉伸试验研究了CrMoV钢焊接接头焊缝金属的局部力学性能,并对焊缝金属进行了微观组织观察和显微硬度测试。结果表明,焊缝金属呈现不均匀的微观组织分布;焊缝金属环向试样的拉伸强度要大于径向和轴向试样的拉伸强度,而焊缝中心所取试样的拉伸强度要小于焊道上所取试样的拉伸强度。结合金相分析得到,焊接接头焊缝金属最薄弱的部位在焊缝中心等轴晶区。

Heterogeneous Mechanical Property and Microstructure of Welded Joints of CrMoV Steel

The local mechanical properties of dissimilar welding joint of steam turbine rotor were investiga-ted by using micro tensile test,and the local microstructure observation and micro -hardness in the joint were characterized and analyzed.The heterogeneous microstructure distribution in weld metal were exhibi-ted and discussed.Higher tensile strength of the circumferential specimens than that of the radial and axi-al specimens in the weld metal was obtained due to the various grains and microstructure distribution;and weaker tensile strength exhibited in the welding center equiaxed grain zone than that in the weld beads because of the weaker grain boundaries.And it can be concluded that the welding center equiaxed grain zone is the vulnerable zone of the weld metal.