Research On Abrasive Wear Characteristics And Mechanism Of Cast Steel Brake Discs For High-speed Trains

As the key component of the braking device of the railway vehicle,the brake disc is directly related to the braking performance of the railway vehicle.The brake discs of rail vehicles running in cold and windy areas are severely worn,which not only increases the maintenance cost,but also affects the braking performance of rail vehicles,and increases the hidden danger of braking.In this paper,the cast steel brake disc of high-speed train is taken as the research object,and the characteristics and mechanism of abrasive wear process are analyzed by the method of finite element simulation and experiment.The specific research contents are as follows:(1)This paper analyzes the wear mechanism of the embedded wear particles in the brake interface of the brake disc,simplifies the geometry of the single wear particles in the wear process,and determines to establish the finite element model of the single wear particles by using the bevel wear particles.The established finite element model is calculated and solved to verify the correctness of the model,so as to ensure the correct description of the elastoplastic deformation and chip fracture on the material surface in the process of abrasive wear.(2)The process of single abrasive wear is simulated,and the distribution of temperature field and stress field in the process of wear is studied and analyzed.At the macro level,the influence of two factors of wear speed and wear depth on the material accumulation height,scuffing force and scuffing temperature on both sides of the scratch is studied and analyzed.At the micro level,the influence of two factors of wear speed and wear depth on the material accumulation height,scuffing force and scuffing temperature is studied and analyzed The effect of the thickness of the surface layer of the scratch on the thickness of the crushed layer.(3)Based on the principle of single variable,the experimental scheme of abrasive wear is designed.A vertical CNC milling machine is used to carry out the scuffing experiment of a single abrasive of the brake disc material.A force measuring instrument is used to measure the scuffing force during the scuffing experiment,and the variation law of the scuffing force under different experimental parameters is studied and analyzed.The morphology of the scratch was observed with a super depth of field microscope,and the three-dimensional and twodimensional cross-section curves of the scratch were derived.The change rule of the material stacking height on both sides of the scratch was studied and analyzed under different experimental parameters.The microstructure of the surface layer at the bottom of the scratch was observed with an electron scanning microscope,and the microstructure of the surface layer at the bottom of the scratch was studied and analyzed under different experimental parameters Law of change.The thesis compares the scratching force obtained in the experimental part,the stacking height of the materials on both sides of the scratches and the change of the surface layer of the scratches with the law of simulation calculation to verify the accuracy of the simulation calculation results.The conclusion of this paper has certain reference significance for revealing the characteristics and mechanism of abrasive wear of brake disc materials.