热处理温度对高钒高速钢显微组织和硬度的影响

Effect of Heat Treatment Temperature on Microstructure and Hardness of High Vanadium High Speed Steel

研究了淬火温度和回火温度对高钒高速钢显微组织和硬度的影响。结果表明:在空冷条件下,当淬火温度低于1040℃时,随着淬火温度的升高,钢的硬度逐渐升高;超过1040℃后,随着淬火温度的升高,其硬度又逐渐降低;同时随着淬火温度的升高,钢中碳化物的数量逐渐减少,马氏体不断粗化,而残余奥氏体含量逐渐增加;在1040℃淬火后,当回火温度低于500℃时,钢的硬度变化不明显;超过500℃后随着回火温度的升高,其硬度先升高,并在520℃时达到最高值,此后钢的硬度又逐渐降低;随着回火温度的升高,马氏体中弥散析出的碳化物数量逐渐增加并聚集长大,同时马氏体和部分残余奥氏体转变为回火马氏体。

The effects of quenching temperature and tempering temperature on the microstructure and hardness of high vanadium high speed steel（HVHSS） were investigated. The results show that with the increase of quenching temperature, the hardness of the steel first increased when the quenching temperatuive lower than 1 040℃ and then decreased when the quenching temperature higher than 1 040 ℃. With the increase of quenching temperature, carbide in the microstructure decreased, martensite became coarsing and residual austenite increased. With the increase of tempering temperature, the hardness of the steel had no obvious change when the tempering temperature lower than 500℃, but when the tempering temperature higher than 500 ℃, the hardness first increased and then decreased and reached a peak value at 520℃. With the increase of tempering temperature, disperse carbides precipitated from the martensite gradurally and grew up together, and at the same time martensite and partial residual austenite transformed into tempered martensite.