YG30硬质合金与45^#钢TIG焊接头组织及抗弯强度的研究

Investigation on the microstructure and bending strength of welded joints of hard alloy YG30 and steel 45

选用Ni-Fe合金和Ni-Fe-C合金作为填充金属对YG30硬质合金与45#钢进行了TIG焊试验。运用扫描电镜、X射线衍射、弯曲力学性能试验等方法对焊接接头的组织形态、物相及抗弯强度进行了研究。结果表明,分布于YG30/焊缝界面区域的η相为M6C型的Fe3W3C,η相的存在是焊接接头抗弯强度低下的原因。选择适当碳含量的Ni-Fe-C合金作为填充金属,能够提高焊接接头的抗弯强度。

TIG welding test of YG30 and steel 45 was carried out with the filling metals made of Ni-Fe and Ni-Fe-C alloys. The scanning electronic microscope (SEM), X-ray and bending strength test were used to analyze the microstructure, phase and bending strength of the welded joints. The results showed that the η phase distributing at the interface of YG30 and weld bead was Fe3W3C, which belonged to the type of M6C. The η phase caused lower the bending strength of the welded joint. By using Ni-Fe-C alloy with proper carbon content as filler metal, the bending strength of the welded joint could be improved.