| 摘要:针对组合式活塞顶-裙结合面发生微动磨损，分析其微动磨损特征。以QT700球墨铸铁活塞裙试样为对磨副，以活塞顶材料42CrMo钢为主要研究对象，开展切向微动磨损试验。研究不同切向位移幅值对摩擦力-位移滞回曲线、磨痕微观形貌、磨损体积的影响规律，得到微动稳定阶段的摩擦因数和磨损率。试验结果表明：在50 N法向载荷、130 ℃环境温度下，当位移幅值为4 μm时，微动位于部分滑移区；当位移幅值为8~40 μm时，微动运行于混合滑移区，微动损伤增大，磨损机制以磨粒磨损为主，易萌生裂纹；当位移幅值增大到50 μm及以上，微动运行于完全滑移区，磨损机制转变为磨粒磨损和疲劳磨损。试验结果为标定仿真模型、完善失效判据提供了直接数据支持，对优化组合式活塞设计具有指导意义。 |
| 关键词: 组合式活塞 42CrMo钢 QT700球墨铸铁 微动磨损 试验 |
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| Experiments of the Fretting Wear of the Contact Surface Between Combined Piston Crown and Skirt |
| CHENG Jiaqi,LIANG Gang,LI Liting,WANG Chunhui,XU Yuxuan |
| Shanghai Marine Diesel Engine Research Institute， Shanghai 201108， China;Shanghai Marine Diesel Engine Research Institute， Shanghai 201108， China;National Key Laboratory of Marine Engine Science and Technology， Shanghai 201108， China |
| Abstract:To deal with fretting wear occurred at the combined piston crown and skirt contact surface，the fretting wear characteristics were studied.Using the sample of QT700 ductile iron piston skirt as the counter pair，and the piston crown material 42CrMo steel as the research object，tangential fretting wear experiments were conducted.The effects of various tangential displacement amplitudes on the friction force-tangential displacement hysteresis loops，micro-morphology of wear tracks，and wear volume were systematically studied.The coefficient of friction and wear rate in the stable phase of fretting was obtained.The experimental results reveal that：Under a normal load of 50 N and an environmental temperature of 130 °C，when the displacement amplitude is 4 μm，the fretting is in the partial slip regime；When the displacement amplitude ranges from 8 μm to 40 μm，the fretting is in the mixed slip regime，with increased fretting damage，and the wear mechanism is predominantly characterized by abrasive wear，predisposing to crack initiation；When the displacement amplitude is increased to 50 μm or greater，the fretting is in the gross slip regime，with the wear mechanism shifting to abrasive wear and fatigue wear.The experimental outcomes provide direct data support for calibrating simulation models and refining failure criteria，and offer significant guidance for the optimization of composite piston design. |
| Key words: combined piston 42CrMo steel QT700 ductile iron fretting wear experiment |
