4Cr5MoSiV1 steel is a new type of high heat mold steel, which can be used as hot forging die, hot extrusion die and die casting die. Since the hot working die is subjected to a large thermal impact force during the working process, the hot metal flows in the cavity to generate strong friction, and the working surface of the mold is in contact with the hot metal for a long time, and the surface contact temperature is high, sometimes even up to 1000°C. Between each work, the forging die is cooled with water or oil, and the mold is subjected to thermal alternating stress of repeated heating and cooling to cause cracking. Therefore, steel is required to have high thermal stability, high high temperature strength and high thermal fatigue resistance, and has good weldability and toughness, high oxidation resistance, high hardenability and small Heat treatment deformability.
The conventional heat treatment process of
4Cr5MoSiV1 mould steel is 1040°C~1080°C. After oil cooling to 500°C ~550°C, the oil is air-cooled. The process of billet warping and cracking occurs during the process, and the toughness of the final heat treatment is not ideal. Therefore, the heat treatment process is the key to improving the service life of 4Cr5MoSiV1
hot work mold steel.
