The Effect Of Rare-earth And Alloying Elements On The Thermal Conductivity Of Austenitic Medium Manganese Steel

The medium manganese steel on the metastability can be produced by reducing carbon and manganese content of high manganese steel.With fair or little loading,Martensitic transformation can be found in the medium manganese steel.Therefore,medium manganese steel has better corrosion resistance in fair or little impact abrasive condition than high manganese steel.In order to enhance the mechanical properties of austenitic manganese steel,the elements of Cr?Mo?N?W and rare earth can be added.Many researches about the effect of these additive elements on corrosion resistance have been conducted at home and abroad.However,the work about the effect of these additive elements on thermal conductivity is little.To explore the effect of these additive elements on the thermal conductivity and corrosion resistance of medium manganese,we have design austenitic manganese steel samples with variable composition contents of Cr?Mo and RE.This work has based the theoretical foundation for the design of easy processing medium manganese.In this test,eight austenitic manganese steel samples with variable composition contents have been cast and treated by water toughening.After water toughening,the thermal conductivity of medium manganese has been test.The general corrosion properties of the samples were tested with a MLD-10 wear tester under the impact energy of 2J.The working time about the test is one hour.The lost weight of the samples has been measured.Surface hardness and work hardening depth of the samples has been measured by micro hardness tester.Microstructure and fracture surface and distribution of carbide are investigated by means of XRD TEM and metallograph scanning electron microscope.Testing results show that,when the content of Cr is more than 4%,the carbon atoms will be gathered in the grain boundary formed a lot of carbide,and it is hard to be eliminated by water toughening treatment,which is not conducive to improve the thermal conductivity.However,the addition of Cr can intensify the order of C-Mn cluster.So the thermal conductivity of high manganese steel can be improved.When the additive of Mo is 2%,globular carbidewhich can improve the thermal conductivity of medium manganese steel.At the same time,as the precipitation of carbon atoms in austenitic manganese steel,thermal conductivity can be improved.The thermal conductivity and corrosion resistance of medium manganese can be both intensified by the interaction of rare earth and alloying elements.