Simulation Optimization And Experimental Study On Heat Treatment Of G20CrNi2MoA Bearing Rings

Performance of high-end bearings depends not only on the chemical composition of the material,but also on the development and application of heat treatment technology.At present,some research work has been carried out on the carburizing heat treatment process of G20 Cr Ni2Mo A carburizing bearing rings in China,but the determination of key control indexes in the standard is still lack of scientific understanding.This article takes the axle box bearing ring of the EMU as the research object,through the methods of test,simulation analysis and comparison,the control specification of key control index parameters of heat treatment of carburized bearing steel is studied and established.Based on this,the simulation and optimization research of heat treatment process is carried out.The main research contents of this thesis are as follows:Firstly,test the bearing outer ring at home and abroad of hardness,carbon content,microstructure and the curve of the hardening layer and residual austenite content indicators,and by using statistical method to determine the hardness of the bearing ring,the surface carbon concentration and residual austenite content,microstructure and grain size,and the curve of the hardening layer on heat treatment,such as the key control index of control specification.Secondly,the simulation calculation model of the whole process of carburizing-quenching-tempering-secondary quenching and tempering of bearing rings was established,and the reliability evaluation of the simulation results was completed through the test data of bearing rings processed by the current technology.Thirdly,according to the characteristics and parameter control range of the heat treatment equipment in the bearing plant,nine groups of simulation process schemes were designed and carried out simulation optimization research for the carbon potential,temperature and cycle in the carburizing heat treatment.According to the determined optimization objective and optimization function,the simulation results of different process schemes are compared and analyzed,and the new heat treatment process scheme is finally determined.Finally,bearing factory according to the optimized heat treatment process,the implementation of the carburizing heat treatment technology of bearing ring test,and to handle new technology scheme of bearing ring of hardness,microstructure and grain size,surface carbon concentration,content of residual austenite and the curve of the hardening layer control indexes such as the test,the results show that the The test results of each index are in accordance with the control specification of heat treatment index,and the simulation results are in good agreement with the test results.