摘要
目的在冬季雨雪复杂恶劣气候的影响下,高铁制动盘面易出现制动距离延长,甚至制动失效等问题,该问题严重影响了列车运行的安全性和可靠性,有必要开展高铁制动盘Q345B在干燥和水润滑环境下摩擦磨损性能的影响研究。方法利用COMSOL有限元软件,建立干摩擦和水润滑制动摩擦模型,探究制动摩擦过程中水介质对温度场的影响。同时,基于MMW-1A摩擦磨损试验机,开展不同表面状态(干摩擦、水润滑)及不同压力载荷下的摩擦磨损实验,并对磨损表面展开SEM及三维形貌观测,通过EDS测量磨损表面元素分布。结果研究发现润湿界面的温度低于干摩擦界面温度,润湿界面温度约降低了33.3%,且温度分布更为均匀。同时,相较于干摩擦环境,在润湿界面下摩擦因数最大降低了约30%。随着载荷的增加,在干摩擦环境下磨损日益严重,在重载工况下润湿表面的磨损深度仅为干摩擦表面的29%,且表面粗糙度仅为干摩擦环境下的57%。干摩擦磨损类型主要为疲劳磨损、黏着磨损、氧化磨损,在润湿界面下磨损类型主要为磨粒磨损。结论水的冷却和润滑作用降低了热应力,减少了黏着磨损、氧化磨损,且水润滑和摩擦生热环境促进了氧化铁(Fe_(3)O_(4)、Fe_(2)O_(3))、氧化铜(Cu_(2)O、CuO)与水分子混合物的摩擦化学产物的形成,在摩擦过程中形成了一层保护膜,大大降低了摩擦副与水之间的附着力。
Under the complex and adverse conditions of winter rain and snow,braking discs of high-speed trains may result in extended braking distances and even lead to brake failure.This issue seriously compromises the safety and reliability of train operations.Therefore,it is necessary to research the influence of dry and water-lubricated conditions on the friction and wear performance of the Q345B steel used in braking discs of high-speed trains.The braking friction models under dry friction and water lubrication were established by COMSOL finite element software.The temperature distribution patterns at the dry friction interface and the wet interface were compared at different time points to investigate the influence of the water lubrication medium on the temperature field.Friction and wear experiments under different surface conditions(dry friction and water lubrication)were conducted based on the MMW-1A friction and wear testing machine.The load magnitudes for the pin-on-disc wear tests were calculated according to the actual braking loads(32,23,and 14 kN).A comparative analysis was conducted on the variation patterns of the friction coefficient under different loads and surface conditions.A three-dimensional profilometer and scanning electron microscopy(SEM)were employed to examine the micro-morphology of both dry friction surfaces and wet surfaces,thereby analyzing the patterns of surface wear depth evolution and differences in wear types.Simultaneously,an energy dispersive spectroscopy(EDS)analysis was performed on the worn surfaces under different surface conditions to measure the elemental distribution and investigate the differences in tribochemical products.Based on the simulation and experimental findings,a schematic diagram of the wear mechanisms under both dry friction and wet interface conditions was comprehensively established,thereby clearly elucidating the relationship between friction evolution behavior and the wear response mechanism under wet interface conditions.The simulation results reveal that the temperature at the wet interface is lower than that at the dry friction interface,with a more uniform temperature distribution observed under lubricated conditions.Specifically,the temperature at the lubricated interface is approximately 33.3%lower.Compared with the dry friction condition,the maximum reduction in the friction coefficient under the lubricated interface reaches approximately 30%.As the load increases,wear under dry friction conditions becomes increasingly severe.Under heavy load conditions,the wear depth of the lubricated surface is only 29%of that under dry friction,and its surface roughness is merely 57%of that under dry friction.The main types of dry friction wear are fatigue wear,adhesive wear and oxidation wear.While under water lubrication,the surface of the friction disc is mainly abrasive wear,with abrasive particles detaching form furrows and pits on the surface.This is primarily attributed to the cooling and lubricating effects of water,which reduce the tendency for thermal stress and minimize adhesive wear and oxidative wear.Moreover,the combined action of water lubrication and frictional heating promotes the formation of tribochemical products,such as mixtures of iron oxide,copper oxide,and water molecules.These products create a protective film on the surface,significantly reducing the adhesion between the friction pair and water.
作者
谢永
史立
高和序
刘宇
张生芳
沙智华
XIE Yong;SHI Li;GAO Hexu;LIU Yu;ZHANG Shengfang;SHA Zhihua(School of Mechanical Engineering,Dalian Jiaotong University,Liaoning Dalian 116028,China;Guidaojiaotong Polytechnic Institute,Shenyang 110023,China)
出处
《表面技术》
北大核心
2025年第23期114-126,共13页
Surface Technology
基金
国家自然科学基金(52375169)
辽宁省应用基础研究计划(2022JH2/101300228)
辽宁省教育厅高校基础科研项目(LJ212410150039)。
关键词
水润滑
Q345B
制动盘
有限元分析
摩擦磨损
润湿界面
water lubrication
Q345B
braking disc
finite element analysis
friction and wear
wet interface
