Semi-solid processing of ultrahigh-carbon steel castings

Semi-solid processing using cooling plate technique was developed to produce a high quality ultrahigh-carbon steel (UHCS) components. Microstructure and mechanical properties were investigated as a function of fraction of solid. The microstructure of UHCS was improved using semi-solid processing. A unique homogenized microstructure comprised of fine particles grain size (200–100 μm) was obtained which totally differs from that obtained by ordinary UHCS casting (520 μm particle grain size). Tensile strength of as-cast and heat treated semi-solid processed UHCS is relatively high compared with ordinary one. Both the tensile strength and elongation closely connect with the particle grain size and cementite network changed with fraction of solid. Increasing fraction of solid increases hardness values, which is attributed to the fine and homogenous structure by semi-solid processing.