The appearance of lower hardness at the surface than at the core after through-hardening of steels is known as "inverse quench-hardening." Pioneering work was performed in the 1970s by establishing a simple ...The appearance of lower hardness at the surface than at the core after through-hardening of steels is known as "inverse quench-hardening." Pioneering work was performed in the 1970s by establishing a simple test procedure where cylindrical specimens were cooled by air and brine sequentially to produce the effect. This phenomenon was described in relation to the polymer quenching and its effect to the improvement in the fatigue strength of the steel in the 1990s. The hardening mechanism in the same specimens as the pioneering work was recently examined using a finite element simulation method. However, this work has not been completed for lack of experimental quenching cooling curves for the comparisons. In this study, the same experiments using 20mm diameter cylindrical specimens as those of the pioneering work were conducted to obtain cooling curves and hardness distributions for comparing simulated results. Experimental cooling curves showed a temperature recovery as predicted by the simulation. Also the inverse quench-hardening phenomena were found in the measured and simulated hardness distributions of the specimens.展开更多
通通 Formastor 全自动相变仪研究了高强韧性冷作模具钢(LD_1钢即7Cr7MO3V2Si)的加热转变临界点和 Ms 点,研究了加热温度对碳化物溶解及 Ms 点的影响;通过金相及热力学性能测试研究了 LD_1钢淬火温度对奥氏体晶粒度和淬火硬度的影响.淬...通通 Formastor 全自动相变仪研究了高强韧性冷作模具钢(LD_1钢即7Cr7MO3V2Si)的加热转变临界点和 Ms 点,研究了加热温度对碳化物溶解及 Ms 点的影响;通过金相及热力学性能测试研究了 LD_1钢淬火温度对奥氏体晶粒度和淬火硬度的影响.淬火—回火温度对硬度和冲击韧性的影响.以此为判据制定出不同模具的热处理工艺,并进行了实际生产考核.展开更多
文摘The appearance of lower hardness at the surface than at the core after through-hardening of steels is known as "inverse quench-hardening." Pioneering work was performed in the 1970s by establishing a simple test procedure where cylindrical specimens were cooled by air and brine sequentially to produce the effect. This phenomenon was described in relation to the polymer quenching and its effect to the improvement in the fatigue strength of the steel in the 1990s. The hardening mechanism in the same specimens as the pioneering work was recently examined using a finite element simulation method. However, this work has not been completed for lack of experimental quenching cooling curves for the comparisons. In this study, the same experiments using 20mm diameter cylindrical specimens as those of the pioneering work were conducted to obtain cooling curves and hardness distributions for comparing simulated results. Experimental cooling curves showed a temperature recovery as predicted by the simulation. Also the inverse quench-hardening phenomena were found in the measured and simulated hardness distributions of the specimens.
文摘通通 Formastor 全自动相变仪研究了高强韧性冷作模具钢(LD_1钢即7Cr7MO3V2Si)的加热转变临界点和 Ms 点,研究了加热温度对碳化物溶解及 Ms 点的影响;通过金相及热力学性能测试研究了 LD_1钢淬火温度对奥氏体晶粒度和淬火硬度的影响.淬火—回火温度对硬度和冲击韧性的影响.以此为判据制定出不同模具的热处理工艺,并进行了实际生产考核.
