热处理工艺对高速钢轧辊组织和性能的影响

Effects of heat treatment on the microstructure and mechanical properties of high speed steel roll

研究了淬火温度、冷却方式、回火温度和回火次数对高速钢轧辊组织和性能的影响.结果表明,油冷条件下,淬火温度低于1050℃,随着温度升高,硬度升高,超过1100℃,硬度反而降低.盐浴冷却(盐冷)和空冷条件下,淬火温度对硬度影响结果相似,但获得最高硬度的淬火温度高于油冷时的淬火温度.回火温度低于350℃,高速钢硬度变化不明显,超过475℃,随回火温度升高,硬度升高,并在525℃达到最高值,继续提高回火温度,硬度降低.二次回火后硬度变化不大,三次回火后,硬度反而降低.空冷高速钢轧辊,淬透性差;油冷高速钢轧辊易出现裂纹;盐冷高速钢轧辊,具有优良的淬透性,不易出现裂纹,辊面硬度高,硬度均匀性好。

The effects of quenching temperature, cooling pattern, tempering temperature and tempering time on the microstructures and mechanical properties of high speed steel (HSS) roll have been investigated. The results show that the hardness increases as the quenching temperature increases under oil cooling when the quenching temperature is lower than 1050℃;while the hardness decreases as the quenching temperature increases when the quenching temperature exceeds 1100℃. Under the condition of salt bath ard air cooling, the effect of quenching temperature on the hardness is similar, but the queching temporature at which the highest hardness is obtained is higher than the one in oil quenching. When tempering temperature is lower that 350℃,the hardness of HSS has little change,while it will increase along with the increase of the tempering temperature when the temperature exceeds 475℃ and the highest hardness is obtained at 525℃, and the hardness will decrease as the tempering temperature continues to increase. Two time tempering has little effect on the hardness, three time tempering will decrease the hardness.The HSS roll with air cooling has lower hardenability, cracks are easy to be produced in oil cooling and the HSS roll quenched in salt bath has high hardenability,less cracks, high and homogeneous surface hardness and excellent wear resistance.