Effect of Mo and B on the structure and properties of high chromium cast iron surfacing metal

Abstract

High chromium cast iron with Cr7C3 as the hard phase has excellent wear resistance, and is widely used as an anti-abrasive wear material in the industrial field. High-chromium cast iron surfacing materials are often used to improve the wear resistance of the workpiece surface. The surfacing metal has high hardness and excellent wear resistance, but it has high brittleness and poor crack resistance. In this paper, a flux-cored welding strip of high-chromium cast iron reinforced with boride is designed, using optical microscope (OM), scanning electron microscope (SEM), X-ray diffractometer, micro-hardness and other methods, the amount of Mo, B added to flux-cored welding strip TIG arc cladding surfacing metal was studied the influence of microstructure and performance. The results show that the main constituent phase of the surfacing metal with 43%Mo-7%B4C is Cr7C3, Mo2FeB2 composite strengthening phase, the number of hard phases in the surfacing metal is significantly increased, the size of the hard phase is also significantly reduced, and the distribution is more uniform. The surfacing metal with 34.4%Mo-5.6%B4C addition is mainly the constituent phase is Cr7C3 hard strengthening phase, and Mo2FeB2 is not formed.