Cemented carbides, which are one of the most important composites produced by powder metallurgy, exhibit an excellent performance within metal cutting and rock drilling tools when their hard phase, tungsten carbide, is bound by cobalt. However in recent years, due to health and ethical concerns related to cobalt, there has been a significant focus on designing alternative binders. The martensitic transformation in high-strength steel and its subsequent transformation-induced plasticity effect present a solution to substitute cobalt and improve the overall properties of cemented carbides. However, factors including residual stresses induced by tungsten carbide grains and confined dislocation mean free path significantly affect the martensitic transformation in these composites. In this study, a thermodynamic-based model for the martensitic transformation in steels has been utilized to predict the martensitic start temperature in cemented carbides. The model coupled with a CALPHAD-based approach presents a systematic solution for designing new steel-based binders.