Effect of carbon stabilizing elements on WC cemented carbides with chromium steel binder

Abstract

High price, limited availability and toxicity of cobalt motivates researchers and material engineers to find alternative binder systems for WC cemented carbides. Iron and iron alloys are promising candidates for complete cobalt substitution. Ferritic steels alloyed with chromium can offer an inexpensive binder system to acquire cemented carbides with enhanced oxidation and corrosion resistance. Since Fe and Cr are carbide formers, production of WC-FeCr cemented carbides with a desirable two-phase structure can be problematic. Niobium and titanium are strong carbide formers and well-known alloying elements in steels used to stabilize carbon, preventing formation of unwanted chromium carbide phases. In our work, WC-FeCr was alloyed with elemental Nb and Ti. The phase composition, structure morphology and mechanical properties of prepared cemented carbides were characterized and discussed. As a result, additions of carbon stabilizing elements enabled us to improve structural homogeneity and wear resistance of WC cemented carbides with ferritic a steel binder.