Effect of In-Situ Synthesis TiC on Microstructure and Properties ofHigh Chromium Cast Iron Surfacing Metal

Using self-made high chromium cast iron flux-cored welding tape as welding material, single-layer single-pass surfacing tests were carried out by non-melting inert gas arc welding (TIG) on low carbon steel plate. The effect of in-situ synthesis TiC on the microstructure and properties of surfacing metal was studied by adding different mass fraction (0-5.2%) of ferro-titanitum powder in the flux-cored welding tape powder. The results show that after adding ferro-titanium powder to the flux-cored welding tape powder, there was in-situ synthesis TiC phase in the surfacing metal except Cr₇C₃ hard phase; the size of Cr₇C₃ decreased, the distribution was relatively uniform, and the number increased significantly. When the mass fraction of ferro-titanium powder in the powder was 5.2%, the refinement of Cr₇C₃ in the surfacing metal was the most obvious, and the distribution was the most uniform. With increasing ferro-titanium powder content in the flux-cored welding tape powder, the hardness and wear resistance of the surfacing metal increased. The TiC synthesized in situ in the liquid metal could be used as the heterogeneous nucleation core of Cr₇C₃, which reduced the nucleation resistance of Cr₇C₃ and thus refined Cr₇C₃.