Research On The Mo-bearing High-thermal-conductive Austentic Wear-resistant Manganese Steel

With the continuous progress of science and technology as well as the development of economic globalization,people have higher and higher requirements for the comprehensive performances of materials,and their requirements also become more and more diversified.As the traditional wear-resistant steel,it can stand strong impact,and bear high stress,so no other materials can be compared with it in wear-resistance.However,wear-resistant manganese steel is hard to cut and has a poor thermal conductivity,therefore,when machined,the workpieces are easy to come in thermal deformation,because the heat can not be conducted out,and the cutting speed can not be improved,which makes it difficult to machine.So the thermal conductivity of manganese steel is expected to be enhanced,its cutting speed is to expected to be increased,and its machining performances are expected to be improved.High thermal conductivity can make sure the workpiece has an even distribution of temperature,and that the manganese steel reduces its thermal induced stress as well as cracks and deformation of the products,so the workpieces' endurance character can be strengthened,and the products' service life can be lengthened.Currently,fewer researches have been done on the thermal conductivity of wear-resistant manganese steel.This paper will design and prepare a kind of wear-resistant alloyed manganese steel that is Mo-bearing,and highly thermal conductive to systematically research the microscopic structures and thermal properties of the alloyed steel with different contents of Mo,and in depth analyze the influence that is caused by Mo alloys on manganese steel with Mo=(1%,2%,3%,4%,5%)alloys as the research objects,by using analytic means such as analytical instrument,metalloscope,transmission electron microscope and scanning electron microscope as well as testing means including impact toughness tests,impact wear tests,hardness tests,and so forth.Some innovative achievements which are of engineering value and theoretical value have been achieved,and this has laid both theoretical and practical foundations for the design of highly thermal conductive wear-resistant manganese steel.Research shows that the thermal conductivity of Mo alloyed manganese steel is determined by the dislocation density and the lattice size of the manganese steel.If Mo alloys are added to the manganese steel,the thermal conductivity of the manganese steel will increase by 21.7%,and wear resistance 23.7%compared to Mn13.Measurement shows that the manganese steel with content of 2%Mo alloys has the best comprehensive performances including wear resistance,and thermal conductivity.The defects of the crystals and the sizes of the lattices may influence the thermal conductivity of the manganese steel,especially line defects.The more the line defects are,the lower the thermal conductivity will be.With the increase of Mo contents,granules of composite chemical compounds which contain Mo,Cr,Mn,C,and Si are precipitated out within the matrix.These tiny granule precipitates form into lots of pinning points,which will hinder the movement of dislocation and the growing of crystal particles,and increase the movement of the boundary and sub-boundary of the crystals.Therefore,the defects within the manganese steel,especially line defects are difficult to diffuse,and then the thennal conductivity of the manganese steel is increased.