Direct partial remelting of XW-42 steel in semi-solid zone

Abstract

Microstructure that consists of spheroid grains in liquid matrix is desirable for semi-solid metal forming. In this study, a direct partial remelting from as annealed condition was used to examine microstructural evolution of XW-42 steel prior to thixoforming process. It was found out that M7C3 carbides dissolve inside the semi solid zone (between 1250-1270°C) while M23C6 carbides dissolve completely before entering semi-solid zone. The dissolution of these grain boundary carbides during partial remelting helps the grain spheroidisation of the XW-42 steel samples. Partial remelting at 1300 and 1340°C resulted in the formation of relatively spherical grains with liquid percent around 17%. The results indicate the suitability of these steel as a potential material for thixoforming through direct partial remelting route. © 2010 Asian Network for Scientific Information.