How do H13 mould steel heat treatment
3. The chemical heat treatment of H13 steel if gas nitriding carbon or nitrogen altogether permeability can make the mould to further strengthen, but the nitriding temperature should not be higher than the tempering temperature, to ensure that don't reduce the intensity of heart, so as to improve the service life of mould.
2. The quenching and tempering toughness good die quenching process specification: heating temperature of 1020 ~ 1050 ℃, oil cooling or air cooling, 54 ~ 58 HRC hardness; For hot hard mould quenching technology, heating temperature of 1050 ~ 1080 ℃, oil cooling, 56 ~ 58 HRC hardness. Recommend a tempering temperature: 530 ~ 560 ℃, 48 ~ 52 HRC hardness; Tempering temperature 560 ~ 580 ℃; 47 ~ 49 HRC hardness. Tempering should be twice. At 500 ℃ tempering, tempering the secondary hardening peak, tempering hardness, the highest peak at about 55 HRC, but toughness is the worst. Therefore, tempering process to avoid around 500 ℃ advisable. According to the use of mould need, within the range of 540 ~ 620 ℃ tempering. Quenching heating should be two preheating (600 ~ 650 ℃, 600 ~ 850 ℃), in order to reduce heating process to produce thermal stress.
1. Preliminary heat treatment in the market supply of H13 steel and die steel billet, in the steel mills have prepared annealing heat treatment, ensure the good metallurgical structure, proper hardness, good processability, and no longer annealing. But factory to change after forging has destroyed the original organization and performance, stress, increased the forging must be annealed. Isothermal spheroidizing annealing process for: 860 ~ 890 ℃ heat insulating 2 h, cooling to 740 ~ 760 ℃ isothermal 4 h, furnace cooling to about 500 ℃.
