The Effects Of Modification And Multi-alloyment On The Friction And Wear Properities Of Medium-manganese Steel

Abstract:A Ce modifier is employed to the medium manganese steel Mn7, and then it was alloyed by Cr, Ni, Mo, Nb, Ti. The effect of modification and multi-alloyment on microstructure and mechanical properities of medium manganese steel Mn7have been investigated, Influence of modified and multi-alloyment on sliding friction and wear resistance of medium manganese steel Mn7is studied. The results are as follows:(1)The modification and multi-alloyment treatment refine the medium manganese Mn7, and the carbide in the microstructure is increases, and the medium manganese steel Mn7is austenitizing completely after a heat treatment of water quenching in1050℃and tempering in240℃.(2)The strength and hardness of normal Mn7, modified Mn7and multi-alloyed Mn7are increasing firstly and decreasing finally when the solution temperature is increasing, and3series Mn7steel have the better combination of strength and toughness after a solution treatment at1000℃.(3)Wear mass of three varieties medium manganese steel is increasing with the increasement of load. Under a load of120N, normal Mn7has entered the severe wear stage, which wear mass moves up sharply. With a load of30N,60N and90N, the wear resistance of modified Mn7has a increasement of70%compare to normal Mn7. The wear resistance of multi-alloyed Mn7is2-3times of normal Mn7, and it has not entered the severe wear stage.(4)The main wear mechanism of three series Mn7under a low load(30N) is abrasive wear(micro-cutting) and adhesive wear, with the increasement of laod; abrasive wear(plastic deformation) and oxidative wear appear. Under a load120N, the main wear mechanism of normal Mn7and modified Mn7is abrasive wear(plastic deformation) and oxidative wear, they have entered the severe wear stage because of severe deformation, and while multi-alloyed Mn7hasn’t entered the severe wear stage and oxidative wear does not appear.(5)After sliding friction, normal Mn7has the best work-hardning capacity, multi-alloyed Mn7has the worst. and the strain-induced martensite is found in the surface of normal Mn7under a medium or lower load only by the XRD analysis.