Study On The Effect Of Mo-ce Alloying Treatment On Wear Resistance Of High Manganese Steel Hammer

Because of its good toughness,ductility,strain hardening ability and excellent wear resistance,austenitic high manganese steel has been widely used in crushing,loading equipment in mining industry.Hammer head of large mill equipment due to the large amount of wear and tear,high manganese steel materials commonly used hammer head.However,the wear resistance of high manganese steel is mainly due to its work hardening ability can’t adequately express under the low impact load.Therefore,this topic major research to enhance the wear resistance of crusher hammers,and to solve the hammer head premature failure cause crusher can’t normal operation efficiency is low.ProCAST software was used to simulate and analyze the variation of mold filling,solidification temperature field,and the distribution of shrinkage cavity and porosity in high manganese steel castings.The best casting process was obtained.In this paper,high manganese steel alloyed by Mo single alloying scheme,and the former best Mo content and Ce multiple alloying scheme.Combined with the sample organization and performance,analysis of mechanism,determine the reasonable ratio of alloy.The results are listed.(1)Four kinds of casting process schemes were designed in this paper.The simulation results with ProCAST show that the optimal process parameters were negative pressure 0.04 MPa,casting temperature 1520℃,sand shell selection.The filling process of the other three casting process schemes were not smooth,with some gaps,and shrinkage cavity appeared in the core of the casting.In addition,the microstructure of different alloy high manganese steel castings was simulated.We compared the simulation results of ProCAST and actual production of castings,the results coincided with each other.The castings quality were improved.By simulating the hammer head of high manganese steel with the best process parameters,the correctness of casting process parameters is proved once again.(2)The control samples were prepared for both unit alloying and multiple alloying high manganese steel.One group were treated with water toughness,and the other one were not.The results show that the wear resistance of high manganese steel improved by water-toughening treatment and the carbides were fine austenite,and the bulk carbides were mainly in the grain boundary structure of the latter.Compared with the untreated water toughness samples,the tensile strength increased by 12.59%,hardness increased by14.12%,impact toughness increased by 2 times,wear rate decreased by 0.97%,and wear surface improved greatly.(3)The sample prepared based on Mo element alloying treatment of high manganese steel was taken as comprehensive evaluation indexes,such as microstructure,impact toughness and wear.When Mo was 0.9%,the amount of precipitated carbides was the largest,and the grain size was relatively uniform and small.When Mo was higher than0.9%,the grain size grows slightly.Compared with other groups,this group has the best impact toughness,wear quantity,fracture morphology and wear surface diagram.In a certain range,with the change of Mo content,the performance of the samples showed a trend of increase or decrease,but they were better than the samples without Mo.(4)The sample prepared by multi-alloying high manganese steel based on the optimal Mo content of 0.9%and rare earth Ce were processed.In order to make the multi-alloying effect better,all the samples were treated with water toughness.After water toughness treatment,the degree of microstructure refinement were more obvious.Ce as a strong adsorbent removed impurities effectively,improved the distribution of the second phase,and enhanced the surface hardness of high manganese steel matrix.Compared with the unit alloying treatment,the hardness increased by 15.04%～31.46%,the maximum tensile strength was 621 MPa,while the Mo alloying treatment was 509 MPa.The impact toughness was up to 274.51 J/cm~2and the wear rate was 1.42%.According to the comparison of different alloy treatments,the multi-alloying treatment scheme improved the properties of high manganese steel more significantly,and the high manganese steel samples with 0.9%Mo and 0.18%Ce have the best wear resistance.It provided a theoretical basis for exploring the production of low cost and high wear resistance high manganese steel hammer.