H13 die steel How to heat treat? The following by the professional engaged in mold steel sales and processing Kaiwang For you.
1. The pre heat treatment of H13 steel and die blank supplied in the market has been well done in the steel plant to ensure good metallographic structure, proper hardness, good processability, and no annealing is required. However, the original structure and properties are destroyed and the forging stress is increased after the modification. Therefore, re annealing is necessary.
The annealing temperature is from 890 ℃ to 760 ℃ for 2 hours.
2. Quenching and tempering require good toughness die quenching process specification: heating temperature 1020 ~ 1050 ℃, oil cooling or air cooling, hardness 54 ~ 58hrc; mold quenching process specification requiring thermal hardness, heating temperature 1050 ~ 1080 ℃, oil cooling, hardness 56 ~ 58hrc.
The recommended tempering temperature is 530-560 ℃, hardness is 48-52hrc, tempering temperature is 560-580 ℃, hardness is 47-49hrc.
Tempering shall be carried out twice. When tempered at 500 ℃, the secondary hardening peak appears. The tempering hardness is the highest, the peak value is about 55HRC, but the toughness is the worst. Therefore, the tempering process should avoid about 500 ℃. According to the needs of the die, tempering is better in the range of 540 ~ 620 ℃.
The quenching heating should be preheated twice (600-650 ℃, 800-850 ℃) to reduce the thermal stress in the heating process.
3. If gas nitriding or nitrocarburizing is carried out on H13 steel after chemical heat treatment, the die can be further strengthened, but the nitriding temperature should not be higher than the tempering temperature, so as to ensure that the strength of the core will not be reduced, so as to improve the service life of the die.
That's it H13 die steel Kaiwang has more questions about the heat treatment of steel.