The heat treatment system is: steel bar annealing, steel wire annealing or 830-840 degree oil quenching.
Heat treatment process parameters:
1. General annealing: heating at 790-810 ℃, air cooling after furnace cooling to 650 ℃ - hb170-207
2. Isothermal annealing: 790-810 degree heating, 710-720 degree isothermal, air cooling - hb207-229
3. Normalizing: 900-920 degree heating, air cooling - hb270-390
4. High temperature tempering: 650-700 degree heating, air cooling - hb229-285
5. Quenching: 860 degree heating, oil quenching - hrc62-66
6. Low temperature tempering: 150-170 degree tempering, air cooling - hrc61-66
7. Carbonitriding: 820-830 degrees for 1.5-3 hours, oil quenching, - 60 to - 70 degrees deep cooling + 150 to + 160 tempering, air cooling - HRC ≈ 67
The smelting quality of bearing steel is very high, so the content and distribution of sulfur, phosphorus and non-metallic inclusions should be strictly controlled, because the content and distribution of non-metallic inclusions have a great influence on the life of bearing steel. The higher the inclusion content, the shorter the service life.
On 2018-08-08 11:45:46
