| 摘要 |
The proposed heat treatment process of bearing steel comprises annealing and improvement. Improvement follows after annealing and after manufacture of structural parts from that kind of steel. In the annealing process, first heating of steel at a rate higher than 1 degC/s to a temperature in the range of 750 to 900 degC takes place. Subsequently follows a dwell time on the achieved temperature for at the most 400 s. Then cooling down takes place to temperature at which austenite transformation to ferrite and carbides begins at a rate higher than 0.02 degC/s. Cooling down continues to such temperature and at such a rate that at least in the steel required locality complete transformation of austenite to ferrite and carbides occurs. The cycle of heating, delay and cooling is to be carried out by at least once. Subsequently, cooling the steel to ambient temperature takes place. |
