Research Of Large Bearing Steel About Heating And Controlled Cooling Process

Bearing steel products in the industry，agriculture，national defenseand other fields is widely used. With China’s rapid economic and technologicaldevelopment， bearing steel and continuously improve product quality requirements.Macro-bearing steel billet in which carbon segregation seriously affected the qualityof the finished bearing steel. Thus improving macro-bearing steel billet carbonsegregation situation is particularly important.According to the actual production of a factory site，the paper size260×240mmGCr15bearing steel billet as the research object，respectively，bearing steel billetbasic laws of macroscopic carbon segregation and high-temperature diffusion processsystem on GCr15bearing steel billet carbon segregation of research and analysis.The results were as follows：(1) x1direction radial segregation ratio was6.56%standard deviation, radialdirection x2segregation ratio was4.69%standard deviation，the diagonal direction z1segregation ratio was4.63%standard deviation, the diagonal direction of thesegregation ratio z2MSE4.46%，indicating GCrl5bearing steel billet diagonaldirection macroscopic carbon segregation ratio smaller than the radial carbonsegregation. Edge of the segregation ratio was2.75%standard deviation，the Ministryof segregation than half the mean square error of2.16%，indicating GCrl5bearingsteel slab edge，half portion of macroscopic carbon segregation smaller，more uniformdistribution of carbon.(2) GCrl5bearing steel billet after high temperature diffusion furnace，usingheated below800℃for2h, using heated800~1180℃for2h，1180℃for2hheating technology system can make the carbon bearing steel billet uniformdistribution of elements in the macro carbon segregation significantly improved.(3) The simulation data of cooling process with85mm bearing steel withoptimized can calculate the average temperature and heart rates of2.55℃/s, the heartof the cooling rate below3℃/s, the simulation by ANSYS finite element softwareanalysis, bearing steel bar diameter greater than80mm is not suitable for use in watercooling method to control the formation of carbide network.