On particles and slags in steel casting

Hadfield steel is widely accepted as one of the most important steel alloys utilized in industrial applications where high impact strength and wear resistance is required. Like in most metallic alloys used for component casting, the mechanical properties of Hadfield steel are directly connected with the microstructure of the material. It has been reported that Hadfield steel components with fine microstructure can present up to 30% increased strength and reduced risk of porosity formation during solidification when compared with their coarser microstructure counterparts. In the light-metal alloy and cast-iron industry, one of the most widely used methods for achieving refinement of the microstructure of the material is known as inoculation. As the name implies, inoculation is the practice ofadding selected compounds or alloying elements in a metal melt that have the ability to promote rapid grain nucleation during solidification. Even though it has been proved that inoculation is one of the most efficient methods for the refinement of a wide variety of metallic alloys, it has not yet gained adequate acceptance in the steel casting industry because researchers have not yet been able to identify proper inoculants for steel. The efficiency of the microstructural refinement when inoculating is influenced by several factors like the type of inoculant used and the processing conditions during melting, deoxidation, casting and heat treatment. Following proper deoxidation methods and application of tailored oxidic slags during melting could significantly promote the precipitation of desired inclusions that can act as potent nucleation sites for grains or as grain growth inhibitors. In any case, efficient inoculation is influenced by the complex interaction between the inoculant, the oxide slag, and the melt. The way this interaction happens is in many ways dictated by the chemical and thermophysical properties of the substances involved. Therefore, obtaining accurate values of basic thermophysical properties like ...