Effect of alloying element on mechanical properties and phase composition of hot working die steel
SUN Jian;CAO Kai;School of Metallurgy and Materials Engineering, Jiangsu University of Science and Technology;
Hardness, tensile and impact properties of heat treated three kinds of hot working die steels with different alloying element contents were comparatively investigated to explore the influence of alloying element on their mechanical properties. Phase diagrams of three steels were calculated with software and then strengthening mechanism of the second phase was discussed combined with simulation result and microstructure. The research indicates that H418 steel not only shows the best plasticity and toughness but also shows the highest hardness. H419 steel has the best strength whereas H407 steel has the lowest strength and hardness. H418 steel has the minimum size and the largest amount of dispersed second phase. H419 steel has the maximum size and the most second phase. As the size of the second phase is large, precipitation strengthening is the dominant strengthening effect. As the dispersed second phase size is small, fine grain strengthening is the dominant strengthening effect.