Exo-Inoculant Modification of Secondary Phase Precipitation in H13 Tool Steel

Abstract

Secondary phase carbides in term of type and morphology are considered as the most challenge facing the applications of hot work tool steel. AISI H13 tool steel is one of the most applicable hot work tool steel grades. M23C6, M6C and MC are the common secondary carbides that are forming throughout the martensite matrix of H13 tool steel. In this research, nanoinoculant silicon nitride was added to the molten H13 tool steel to act as an inoculant for the secondary carbide categories through ladle treatment process. By using OM and SEM, it was observed that nanoinoculant has the great impact in the nucleation of secondary carbides into fine shape, in particular M23C6 type. In addition, mechanical tests proved that the nucleation of secondary carbides promotes the mechanical properties of hot work H13 tool steel to its ultimate. Impact toughness of the inoculated H13 tool steel was observed with higher value than that was done at the ordinary H13 tool steel. At the meantime, wear resistance of inoculated H13 tool steel was multiplied two times higher than as delivered H13 tool steel.