Study on the Microstructure and Liquid Phase Formation in a Semisolid Gray Cast Iron

摘要: The development of high-quality semisolid raw materials requires an understanding the phase transformations that occur as material is heated up to state, i.e., its melting behavior. microstructure plays a very important role during processing it determines flow behavior when formed, making thorough microstructural evolution essential. In this study, and in Fe2.5C1.5Si gray cast iron specially designed for thixoforming processes was state were observed using situ high-temperature confocal laser scanning microscopy. At room temperature, alloy has matrix pearlite ferrite with fine interdendritic type D flake graphite. During heating, main graphite precipitation inside grains at austenite grain boundaries; flakes precipitates growing becoming coarser increasing temperature; beginning around 1413 K 1423 (1140 °C 1150 °C). Melting begins eutectic (i.e., carbon-rich phase) continues primary (primary austenite), which consumed temperature increases. composed by coarsened produced semi-continuous liquid network homogeneously surrounding wetting dendrites solid phase, causing detach from each other producing intended globules immersed liquid.