Material Design And Property Research Of Lining Plate For Gyratory Crusher

Gyratory crusher is mainly used for crushing ores as common equipment.It is constituted by fixed cone lining plate and dynamic cone lining plate.Ores are crushed through the extrusion and the friction generated between fixed cone lining plate and dynamic cone lining plate,so the service performance requirements of fixed cone lining plate and dynamic cone lining plate is very high.The material of lining plate is high manganese steel in certain ore of Ansteel.But high manganese steel shows poor wear resistance under low impact load conditions in actual work.The main reason is that the stability of austenite in high manganese steel is so high that,the martensitic transformation can not be induced under low impact load.So high manganese steel is only applied under high impact condition.Therefore,this paper carried out the following research works to solve the question.(1)According to the characteristics of austenitic manganese steel,four kinds of Mn8Cr2Si steel with different carbon content were designed.The effect of water toughening treatment on the micro structure and property of Mn8Cr2Si steel with different carbon content was studied.The microstructure,mechanical properties,wear resistance and corrosion resistance of Mn8Cr2Si steel were studied with the change of carbon content.The optimum carbon content of Mn8Cr2Si steel was 0.8%.(2)The relationship between mechanical property and grain size of Mn8Cr2Si steel was studied by using optical microscope,scanning electrical microscope(SEM),and X-ray diffractometer(XRD).Austenite grain size is gradually refined with the increase of carbon content.But when the carbon content was more than 0.8%,the grain started to be coarse.Due to the refinement of austenite grain,the total area of grain boundaries increased and the stress concentration was reduced,which suppressed the formation and propagation of cracks.Therefore,the finer the austenite grains,the better the mechanical property was,and the upgrade of mechanical property will help to improve the wear resistance of Mn8Cr2Si steel.(3)The abrasive wear test of Mn8Cr2Si steel and Mn13 high manganese steel was carried out under different impact energy by using MLD-10B dynamic load abrasive wear testing machine.The study showed that when impact energy is less than 2J,the wear resistance of Mn8Cr2Si steel is better than that of Mn13 high manganese steel.And when the carbon content is 0.8%,the wear resistance of Mn8Cr2Si steel is better than other Mn8Cr2Si steel.The surface induced martensite phase transformation after impact abrasive wear.The content of martensite increased with the increase of impact energy,which helps to improve the work hardening capacity.(4)SEM was used to investigate the morphology of wear surface and subsurface in order to study the wear mechanism.It was found that impact abrasive wear of Mn8Cr2Si steel was compound action,including plastic deformation,fatigue wear and chisel wear.Some grains were easy to be embedded into the substrate during the plastic deformation process.These grains will become a source of stress concentration.Fatigue crack will gradually grow and propagate to the wear surface under the circulation impact,which causes large impact-flaking at last.(5)In order to eliminate the quenching stress of Mn8Cr2Si steel produced during quenching process,the effect of tempering temperature on micro structure and properties of Mn8Cr2Si steel was studied.The optimum tempering process was 250?+5h and air cooled to room temperature.Because the internal stress is eliminated when tempering at low temperature(250?),the mechanical property of Mn8Cr2Si steel was further improved.These studies above showed that Mn8Cr2Si steel not only had excellent wear resistance performance under low impact condition,but also had good corrosion resistance.So it can meet the requirements of the liner plate of gyratory crusher under low impact condition.