The invention discloses a preparation process of high
alloy hot work die steel and belongs to the technical field of
metallurgy. A certain gap still exists between existing domestic high
alloy hot work die steel and materials manufactured by foreign manufactures in the aspects of
molten steel purity, constituent uniformity, structural
fineness and dimensional accuracy. According to the preparation process, in the electroslag-remelting
smelting process, the
diameter of a crystallizer serves as a key parameter, and the mean
melting rate of the
smelting process is set through the
diameter of the crystallizer; by raising the
heating temperature of a steel
ingot and prolonging
retention time of a high-temperature section, nonuniformity of constituents of the steel
ingot is remarkably reduced; an
operation mode including three times of upsetting and three times of drawing-out is adopted for
forging; according to a calculation method of the upsetting ratio, the ratio of heights, obtained before and after upsetting is conducted, of the steel
ingot is adopted, operation can be easy and convenient to conduct, and the upsetting purpose and effect can be easy to achieve; the heat treatment temperature of
quenching conducted after
forging is completed is raised, and more alloying elements can be dissolved into
austenite on the basis that a certain amount of
carbide is reserved; and annealing is conducted through
two temperature sections, and a spheroidized structure can be uniformly refined.