Investigation on effect of different types of inoculants on the solidification of ductile cast iron using thermal analysis

Purpose Producing superior-quality ductile cast iron demands the use of various intricate inoculants. In addition to iron and silicon, these materials also include alloying elements like calcium, barium, cerium, bismuth and zirconium. These elements are effective in minimizing carbide solidification and enhancing the formation of eutectic cells, thereby resulting in improved cast iron quality. Design/methodology/approach This article discusses the findings of an investigation on how various inoculants impact critical thermal analysis parameters such as undercooling, recalescence and their correlation with the nucleation of graphite nodules and shrinkage tendency. Findings For the study, five distinct inoculants with varying active components in their chemical composition were utilized. The particular formulation of the inoculant has a notable impact on the extent of undercooling during the solidifying process of ductile cast iron. Investigation indicates that incorporating inoculant reduces the temperature at which austenite dendrites form and raises the eutectic freezing temperature. Upon analyzing the microstructure, it is found that the inclusion of inoculation led to a rise in the nodule count from 103 to 272 nodules. Originality/value An increased graphite factor, which denotes the growth of graphite nodules during the subsequent stage of the eutectic reaction, supports the benefits of inoculation. Ce and Bi-inoculation have increased the growth of graphite nodules in the cast area during solidification compared to other inoculant formulations. This enhanced production helps in decreasing the size of macroporosity.