Study On Wear Resistance Of High Manganese Steel Lining Plate Treated By W-Y Alloying

Ball mills have been widely used in various industries.In the wear-resistant materials consumed in our country every year,the proportion of ball mill lining plate is very large.Under the condition of fast construction speed and high standard,the performance requirements of wear-resistant materials are very high.The quality of the liner is directly related to the service life of the ball mill,so it is very necessary to study the wear resistant material of the liner.High manganese steel is widely used in wear resistant materials because of its wear resistance under work hardening ability.However,high manganese steel also has part of its shortcoming,that is,its wear resistance is not good under low stress,which can not meet the requirements of use.In order to improve the wear resistance of high manganese steel under medium and low load,the high manganese steel was treated by tungsten unit alloying,and its microscopic analysis and performance test were carried out by means of metallographic microscope,scanning electron microscope,hardness tester,tensile tester and friction and wear tester.Under the condition that the comprehensive properties meet the requirements,the best ratio of tungsten element content for wear resistance of high manganese steel is obtained.Then on the basis of the best ratio of tungsten content,compound modification of yttrium was carried out.Thus,the optimum ratio of tungsten and yttrium element content for wear resistance of high manganese steel is obtained.The effects of alloying elements on mechanical properties of high manganese steel were studied,and the mechanism of alloying elements was discussed.The research conclusions are as follows:(1)In this experiment,the amount of alloy precipitates produced by ordinary high manganese steel after tungsten alloying is more than that of ordinary high manganese steel,and the casting grain is obviously refined.The size of inclusions is reduced,and their shape and distribution are improved.With the addition of rare earth yttrium,the grain size of high manganese steel decreases first and then increases.The number of inclusions is reduced and the molten steel is purified.After water toughening treatment,carbides in high manganese steel are basically dissolved and the obtained structure is single austenite.Alloying treatment has an important effect on grain size,size,morphology and distribution of inclusions.(2)After tungsten alloying,the hardness and tensile strength of high manganese steel increase with the increase of tungsten content under the combined effects of fine grain strengthening and dispersion strengthening,while the impact toughness increases first and then decreases.After the addition of yttrium compound modification,the hardness of yttrium increases with the addition of yttrium,and the impact toughness and tensile strength show a trend of first increasing and then decreasing,which meet the requirements of use.The mechanical properties of the alloyed specimens are higher than those of the common specimens.(3)Compared with ordinary high manganese steel,the wear rate of high manganese steel decreases by 4.4%～17.8% in the case of tungsten alloying,and by 10.0%～27.5% in the case of tungsten-yttrium composite modification.Compared with ordinary high manganese steel,the wear resistance of the steel has been improved to varying degrees,which is the result of the comprehensive effects of fine grain strengthening,solid solution strengthening and second phase particle strengthening.(4)In this experiment,the microstructure and mechanical properties of high manganese steel before and after water toughening treatment were compared to prove the feasibility of water toughening treatment.Comprehensive comparison of the results of the two experiments showed that the high manganese steel with 1.2% tungsten and 0.12% rare earth yttrium content had the best wear resistance and was more suitable for actual production.