Effect of Annealing on the Structure and the Hardness of Die Steel with a Controllable Austenitic Transformation during Operation

Medium-carbon (0.44% C) steel with a controllable austenitic transformation during operation is investigated. It differs from a commercial 4Kh2N5M3K5F (EP930) steel in a high content of manganese, the element that decreases the α → γ transformation temperature and increases the stability of supercooled austenite. Manganese partially substitutes for deficient nickel. The effect of heat treatment on the structure and the hardness of the steel is investigated. Heat treatment conditions are proposed to reduce the hardness of the initial hot-rolled steel for subsequent machining.