滑动速度对团球共晶体增强奥氏体钢基自生复合材料摩擦学性能的影响

利用MPx-2000型主轴盘销式磨损实验机和扫描电子显微镜(SEM)研究了相对滑动速度对团球γ (Fe，Mn)3c共晶体增强奥氏体钢基自生复合材料(EAMc)摩擦学性能的影响．实验表明，在干摩擦磨损工况下，EAMc对G45钢摩擦系统的摩擦系数随相对滑动速度的增加呈递减趋势；而磨损率呈递增趋势，但始终远低于奥氏体中锰钢(单一奥氏体相)；并且，随着相对滑动速度的提高，EAMC与中锰钢磨损量的差值呈递增趋势．通过对磨损表面和磨屑形貌的分析，发现EAMC在低载下主要磨损机制是磨粒磨损与剥层磨损；高载下的磨损机制主要为剥层磨损与氧化磨损．对偶件之间的粘着作用随相对滑动速度的提高而增加．运用临界转变温度理论与Archard磨损理论分析了相对滑动速度对EAMC摩擦学性能影响的机制．

EFFECT OF SLIDING VELOCITY ON THE FRICTIONAL BEHAVIORS OF IN SITU GRANULAR EUTECTICS REIN FORCED AUSTENITE STEEL MATRIX COMPOSITES

The effect of sliding velocity on the friction behaviors of in situ granular 7+(Fe, Mn)3C eutectics reinforced austenite steel matrix composites (EAMC) has been investigated by the pin-on disc dry sliding tests and scanning electron microscopy (SEM) observation. Results show that the frictional coefficient of the frictional system of EAMC against steel G45 decreases with the increment of sliding velocity, and the wear rate of EAMC increases with it. However, the wear rate of EAMC is much lower than that of austenite medium Mn steel (a single austenite phase), and the difference between the wear rates of EAMC and austenite medium Mn steel increases with the increment of sliding velocity. The dominant wear mechanisms of EAMC are abrasive wear and delamination wear at lower normal load, and oxidative wear and delamination wear at higher normal load by the observation of worn track and wear debris. Adhesion between EAMC and G45 is enhanced with the increment of the sliding velocity, so the amount of debris on the worn track increases with it. The mechanisms of influences of the sliding velocity on the frictional behavior are analyzed with the critical transition temperature theory and Archard wear theory.