摘要
针对变轨距高速列车锁紧机构的微动损伤问题,开展了表面工程防护研究.基于抗微动损伤的表面强化原则,对试验基材(35CrMo钢)进行等离子氮化处理及性能表征.采用自主研制的模块化多功能微动磨损测试系统,在干态及润滑工况下开展了微动磨损试验,揭示不同工况下离子氮化表面的磨损行为、能量耗散和损伤机理.结果表明:与基材相比,离子氮化表面的耐磨性显著提高,其主要磨损机理为磨粒磨损、剥层和氧化磨损.离子氮化处理生成的高硬度且粗糙的化合物层有利于在微动接触界面形成第三体磨屑床,发挥固体润滑作用.此外,适当添加的润滑脂能对磨屑形成分散和包覆,产生协同润滑作用,使基体磨损率降低约60%.研究结果为轨道车辆关键部件抗微动表面工程防护提供理论数据和应用参考.
The service reliability of the locking mechanism,as a key component of variable-gauge bogie,directly affects the operation safety of the variable-gauge high-speed train.Surface engineering protection was experimentally investigated in this work to solve the fretting damage issue of the locking mechanism in actual service.The test substrate(35CrMo alloy steel)was subjected to plasma nitriding treatment and performance characterization on the basis of the principle of surface strengthening against fretting damage.The tangential fretting wear tests under dry and grease lubrication conditions were performed using a self-developed modular multi-functional fretting wear test system.Three displacement amplitudes of 10,30,and 60μm were implemented in the tests,the normal load was maintained at 20 N,and 5000 test cycles were performed at a frequency of 2 Hz.Subsequently,the surface morphologies and tribo-chemical state of the fretting wear region were comprehensively analyzed by scanning electron microscopy,white-light interferometry and X-ray photoelectron spectroscopy.The wear behavior,energy dissipation,damage mechanism of the substrate and plasma-nitrided surface under different working conditions were revealed.Results indicate thatε-Fe2-3N andγ’-Fe4N phases form a dense compound layer of about 8μm thick on the plasma-nitrided surface,and the effective nitriding layer depth reached 0.4~0.5 mm,which increased the surface hardness of the substrate by more than 93%.The wear mechanisms of plasma-nitrided surface under dry conditions were mainly abrasive wear,delamination,and oxidation wear.The micron-scale spherical ferric nitride particles formed by plasma sputtering easily peel off under the action of tangential cyclic stress.They were collected by surface texture to form a third-body abrasive bed,which played a solid lubrication role in the contact interface.Especially in the large-displacement fretting slip region(D=60μm),the friction coefficient and dissipation energy of the plasma-nitrided surface were reduced by 18.5%and 10%compared with those of the substrate,which showed an excellent anti-friction effect.Furthermore,the delamination wear on the plasma-nitrided surface disappeared under grease lubrication condition,and slight abrasive wear and oxidation wear were the main wear mechanisms.Notably,the frictional dissipation energy and wear rate of the plasma-nitrided surface were reduced by about 28.6%and 60%compared with the substrate due to the synergistic lubrication effect formed by the interaction between the grease and third-bodies on the fretting interface.The abovementioned results indicated that the performance of plasma-nitrided surface to alleviate fretting damage was significantly improved under the same service conditions and vibration energy input.This research provided theoretical data and application references for antifretting surface engineering protection of railway vehicle key components.
作者
贺继樊
任岩平
白崇成
彭金方
蔡振兵
刘建华
朱旻昊
HE Jifan;REN Yanping;BAI Chongcheng;PENG Jinfang;CAI Zhenbing;LIU Jianhua;ZHU Minhao(Tribology Research Institute,Traction Power State Key Laboratory,Southwest Jiaotong University,Sichuan Chengdu 610031,China;Guangdong Jiangmen Supervision Testing Institute of Quality&Metrology,Guangdong Jiangmen 529000,China;School of Materials Science and Engineering,Southwest Jiaotong University,Sichuan Chengdu 610031,China)
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2023年第1期18-29,共12页
Tribology
基金
国家自然科学基金项目(51627806)资助。
关键词
锁紧销
微动磨损
等离子氮化
脂润滑
动态响应
磨损机理
locking pin
fretting wear
plasma nitriding
grease lubrication
dynamic response
wear mechanism