ダイカスト金型用高信頼性熱間ダイス鋼“DHA1-ES”

Long life die casting die steels have been required to reduce die cast product cost. The main life limiting factor is premature failure. To obtain higher fracture resistance, high reliable hot work die steel, "DHA1-ES", has been developed. Generally, crack susceptibility is estimated by the Charpy impact value. It is cleared that clean and homogenized steel shows higher Charpy impact value. To improve the toughness the manufacturing process of this steel is optimized such as melting, forging and heat treatment. Though DHA1-ES has the same compositions as those of JIS SKD61, its Charpy impact values, dispersion and anisotropy are improved remarkably. Furthermore, low cycle fatigue life of this grage is longer than JIS-SKD61. It is expected that DHA1-ES is widely used in die casting industry with high reliability.