A series of verifications and calculations of solidification courses, equilibrium phase fractions and their compositions for 15Cr system high chromium cast iron with different ratios of chromium content to carbon content were carried out using Thermo-Calc software, and the microstructure characteristics and its influencing factors of the cast iron were illustrated based upon above equilibrium phase calculations. The results indicate that it's feasible for the adjustments of foundry technology performance, equilibrium phase fractions and their compositions for 15Cr system high chromium cast iro...