Abstract: Effect of different quenching and tempering temperatures on the impact property of the 20Cr13 steel at room temperature and -40 ℃ was studied by means of metallographic microscope and scanning electron microscope. The results show that when the quenching temperature is the same, as the tempering temperature rises from 500 ℃ to 700 ℃, the tensile strength of the specimen decreases gradually, impact properties first decreases and then increases. When the quenching temperature drops from 1030 ℃ to 1000 ℃, at the same tempering temperature, the tensile strength of the specimen changes little, but the impact properties at room temperature and －40 ℃ improves.

Key words: 20Cr13 steel, quenching and tempering temperature, impact properties, microstructure