一种Cr25系耐热钢的组织及磨损行为研究

Study on Microstructure and Wear Behavior of Cr25 Heat Resistant Steel

采用金相显微(OM)、X射线衍射(XRD)、扫描电镜(SEM)、万能力学试验机以及摩擦磨损试验等方法,研究了一种Cr25系耐热钢的组织、相结构、力学性能以及在室温、100℃、260℃下的摩擦磨损特性。研究结果表明:该种Cr25系耐热钢由α相和(Fe·Cr)_(23)C_6(KI)型碳化物相组成,其室温抗拉强度高、塑性差,冲击韧度低于6 J/cm2。在室温下,合金的磨损机制为磨粒磨损,随着磨损温度的增加,摩擦热效应增强,合金的磨损机制逐渐转变为磨粒+粘着磨损;摩擦系数由室温下的0.6逐渐降低到100℃下的0.4,到260℃时,其摩擦系数低至0.35,且其未随磨损时间的延长而显著变化;磨损量随磨损温度的增加逐渐降低。

The microstructure and properties of the Cr25 heat resistant steel were investigated. The microstructure was analyzed by optical microscopy(OM), X-ray diffraction(XRD) and scanning electron microscopy(SEM). And the mechanical properties were conducted by a universal mechanical testing machine. The friction and wear features at room temperature, 100 ℃ and 260 ℃, respectively were studied using a friction and wear tester method. The results show that the Cr25 heat resistant steel consists of α-Fe and(Fe·Cr)_(23)C_6(KI)carbide phases. Tensile strength at room temperature is high and the ductility is poor, and the impact toughness is lower than 6 J/cm^2. The wear mechanism of the alloy is abrasive wear at room temperature. With the increase of wear temperature, the friction heat effect is enhanced, and the wear mechanism of the alloy is gradually changed into abrasive grain and adhesive wear. The friction coefficient decreases gradually from 0.6 to 0.35 with the increase of temperature from room temperature to 260 ℃. And the friction coefficient does' t change significantly with the prolonging of the wear time. The wear quantity decreases with the increase of the wear temperature.