Study On Heat Treatment And Shot Peening Process Of Elastic Boom Of High-speed Railway Traction Device

The high-speed traction device elastic boom is one of the key components of high-speed rail.It can alleviate the impact and make the vehicle run smoothly,which plays an extremely important role in ensuring the safe operation of the vehicle.However,due to the late start of high-speed railway technology in China,the performance of the elastic boom can not meet the requirements,especially the fatigue life is not up to the requirements,so it still needs to be imported from abroad.Therefore,the main content of this paper is to optimize the elastic boom structure by finite element analysis and carry out detailed research on its heat treatment and shot peening process to meet the comprehensive performance requirements of elastic booms,in order to accelerate the process of full localization of high-speed rail in China.In this paper,the elastic boom structure of CRH380 high-speed train is taken as the research object.Firstly,the elastic boom model was established by the three-dimensional software Solidworks.The static and dynamic analysis was carried out by the finite element analysis software Workbench,and the elastic boom structure was optimized.The results show that the designed elastic boom structure meets the static strength requirements and meets the safety requirements after optimization.The The heat treatment process of the elastic boom was studied.The results show that the critical coarsening temperature of austenite grains is 910 ?;compared with other temperatures,the martensite formed at 880 ? is dense,and the strength and hardness are peak;the hardness is related to the tempering temperature.The increase is gradually decreased,and the change trend of yield strength and tensile strength with increasing tempering temperature is firstly increased and then decreased.When the tempering temperature is 460 ?,the yield ratio is the highest and the performance is the best.Finally,the optimal heat treatment process of the elastic hanger was determined,that is,the oil was cooled after heating at 880 ? for 1 h,and then air-cooled after heating at 460 ? for 2 h.The shot peening process of the elastic boom was studied.The results show that the parameters of shot peening,namely shot peening time,injection pressure and spray angle,have a great influence on the residual stress field,while the spray angle has little effect on the surface roughness.The residual compressive stress on the surface of the workpiece after shot peening for 10 min tends to be saturated and has the lowest surface roughness value.The effect of shot peening on the fatigue performance of the workpiece was further studied.It was found that the fatigue life of the workpiece was greatly improved after shot peening,and the maximum increase was 88.7 %.The larger the injection pressure,the greater the fatigue life of the workpiece.The final shot peening process has a spray angle of 90°,a shot peening time of 10 min and an injection pressure of 6 bar to ensure maximum fatigue life of the elastic boom.Based on the finite element software ABAQUS,the blasting process was simulated using the display dynamics algorithm.By comparing with the results of the shot peening test,it is found that the residual compressive stress field has the same regularity and the maximum error is only 8.9%.Therefore,under the condition of limited test conditions,the finite element model can be used to simulate the influence law of residual stress during shot peening,which provides an effective theoretical basis for actual production.