Research On High Temperature Wear Resistance Of GCr15 Bearing Steel Ball After Intensive Grinding

Bearings are the core functional components of high-end equipment,known as the "equipment chip",and the steel ball is one of the most critical parts of the bearing.Domestic existing technology can not make high-end equipment bearings to achieve "high precision,high efficiency,high life,high strength,high reliability" and other performance requirements,is recognized as the "neck" technology,and 80% of bearing failure are from the steel ball failure,so explore the bearing steel ball Therefore,it is imperative to investigate the surface performance of bearing balls.This paper proposes a new steel ball strengthening process based on the strengthening grinding process technology-steel ball strengthening grinding process technology.In this paper,the strengthening mechanism of steel ball strengthening grinding is studied through theoretical analysis,finite element simulation and experimental verification.The influence law of wear resistance of GCr15 steel balls under a high-temperature environment after steel ball strengthening grinding processing is investigated.Then the optimal process parameters are explored,and the specific research results are as follows:(1)Based on the reinforced grinding processing technology,the steel ball reinforced grinding collision-stress theory was derived by combining Hertzian collision theory.(2)Through ABAQUS finite element numerical simulation,a steel ball reinforced grinding processing model was established to explore the influence of different grinding tank inner wall structures and different rotational speeds on the surface stress distribution of GCr15 steel balls in the grinding tank and to analyze the movement law of GCr15 steel balls,in which the maximum residual stress value of simulation group No.6 was 612.8MPa.(3)The GCr15 steel balls were tested by steel ball strengthening and grinding equipment.Each specimen’s surface morphology,grain size,residual stress,micro-hardness and other performance indexes were measured and analyzed.The results show that the surface of the specimens after steel ball strengthening and grinding showed many irregular micro-pits and extrusion ridges,the grain size of the surface tissue had different degrees of refinement,and dislocation density increased.The residual stress value of the surface layer also increased significantly,including the enormous residual stress value of-612.2MPa in specimen No.7.The micro-hardness value at 20μm from the surface layer was also the largest,916.7 HV.Two groups of specimens with the best strengthening effect and a blank control group were selected and subjected to frictional wear tests at 25°C,200°C,400°C and600°C by using a multi-functional vertical friction and wear tester to explore the influence of strengthening and grinding of steel balls on the wear resistance of GCr15 steel balls by analyzing their average friction coefficient,wear scar shape and wear amount.The results showed that the average friction coefficients of test group No.7 at different temperatures were 0.46,0.50,0.32 and 0.11.The width of wear marks was754.13μm,767.52μm,658.35μm and 640.83μm,and the wear amounts were 1.77 mg,2.16 mg,1.27 mg and 1.01 mg,which were the smallest;with the increase of temperature,it showed a trend of slight increase and then decrease,and showed the best wear resistance and the mechanism of the action of high-temperature friction wear was studied.