Hot working die steel is mainly used for stamping dies of various stainless steel plates, silicon steel sheets and aluminum plates.

The main difference lies in the difference of heat treatment process and quenching hardness.

(1) cold working die steel

Cold working dies include cold stamping dies, cold extrusion dies, bending dies and trimming dies. In the process of working, they have to bear high pressure, bending force and certain impact force, and at the same time have severe friction with the blank, so they must have high hardness, high wear resistance, sufficient strength and toughness, and at the same time have small deformation and high hardenability after heat treatment. Commonly used materials are 9Mn2V, Cr 12, Cr 12MoV, Cr6WV, 65Mn, 9SiCr, GCr 15SiMn and CrWMn. The heat treatment process is quenching and low temperature tempering, and the hardness is relatively high (above 58HRC).

(2) Hot-working die steel

Hot working dies include hot forging dies, hot upsetting dies, hot extrusion dies and die casting dies. According to the working conditions, they should have high high-temperature mechanical properties, sufficient high-temperature strength, toughness, hardness and wear resistance, good thermal fatigue resistance, high hardenability, good manufacturability and oxidation resistance. The common materials of Junrui die steel are 5CrMnMo, 5CrNiMo, 3Cr2W8V, H 13, 5SuMnMoV, 4SiCrV and so on. It can be seen from the heat treatment process curve of 3Cr2W8V die casting die that its heat treatment process is complicated and its mechanical properties are determined by tempering temperature. Most of them are tempered at high temperature, and their hardness is controlled at 40 ~ 50 HRC, which meets the needs of work.