Cr12模具钢亚温淬火工艺研究

Study on Intercritical Quenching Processing of Cr12 Die Steel

对Cr12模具钢进行亚温淬火＋回火热处理并测定其力学性能，结合显微组织的观察，研究了亚温淬火及回火对其力学性能的影响。研究结果表明：Cr12钢处于800～920℃亚温淬火时，随着淬火温度的升高，铁素体的量逐渐减少，马氏体的量逐渐增加。导致强度、硬度上升，韧性逐渐降低。亚温淬火时。由于不同淬火温度下获得的两相比例及奥氏体中碳浓度不同，因此回火后钢的抗拉强度并非随淬火温度的降低而单调下降。在保证淬透性的前提下，920℃亚温淬火能满足强度、硬度、冲击韧性等力学性能的要求。

The properties of Cr12 steel treated by intercritical quenching and tempering was measured, and its microstructure was also observed, then the effect of intercritical quenching and tempering on the properties and microstructure of Cr 12 steel. The results show that, with the increase of intercritical quenching temperature in the range of 800-920 ℃, the amount of ferrite decreases and the martensite increases gradually, which results in the increasing of strength and hardness rise and the and decreasing of toughness. The tensile strength of the steel treated by intercritical quenching and tempering does not decrease monotonically with the decrease of the quenching temperature, due to the ratio of two phases and the carbon concentration in austenite obtained in different intercritical quenching temperature are different. When the hardenability can be ensured, the steel quenched at 920 ℃ can meet the strength, hardness, impact toughness and other mechanical performance requirements.