显微组织和环境温度对球墨铸铁磨损行为的影响

摘要

Wear tests for ductile iron were performed by a pin-on-disk high temperature wear apparatus under different temperatures and loads; the effect of microstructure on wear resistance was studied.The composition, morphology and structure of worn surface and subsurface were analyzed by using of EDS, SEM and XRD; the wear mechanism was also discussed.The results show that microstructure had apparent influences on wear behavior of ductile iron.With the increasing hardness of matrix, the critical load for the transition of mild-severe wear greatly increased.With the increasing temperature, the formation of carbon-reducing atmosphere made the amount of oxide on the worn surface decrease.The wear mechanism of ductile iron at room temperature was mainly adhesive wear and grinding abrasion; at 200 ℃, the mechanism was still adhesive wear; the mechanism at 400 ℃ was mainly oxide spalling fatigue.%采用销盘式高温磨损实验机在不同环境温度和载荷下对球墨铸铁进行干滑动磨损试验,研究了球墨铸铁显微组织对磨损性能的影响,呆用SEM和XRD分析磨损表层以及亚表层形貌、成分和结构,初步探讨磨损机制.研究表明,基体组织对球墨铸铁磨损性能有着显著影响.随着基体硬度的提高,轻微磨损向严重磨损转变的临界载荷大大提高.随着环境温度升高,形成碳还原气氛使得磨面上氧化物数量减少.球墨铸铁室温下磨损机制主要为粘着磨损和磨料磨损,200℃时磨损机制仍为粘着磨损,400℃时磨损机制主要为氧化物的疲劳剥落.