Study On Micro-mechanical Simulation And Wear Resistance Of Fe-Cr-C Carbide Morphology

Fe-Cr-C system wear-resistant materials were widely used in the field of industrial wear resistance,in which the Cr/C ratio and carbide morphology is the key factor affecting tribological properties of wear layer.In this paper,the Fe-Cr-C alloy cladding layer with representative carbide content and distribution was obtained by adjusting the ratio of Cr and C.And the finite element model was established based on its real microstructure;X-ray diffraction was used to determine the composition of the tissue,and nano-indentation was used to characterize the micro-hardness and other micro-mechanical properties to obtain the stress-strain curves and parameters of mechanical properties of different carbide and matrix;then the friction and wear tests were performed.At the same time,based on real microstructure,the finite element method combined with Mises yield criterion and shear failure theory was used to simulate the sliding wear and analyze the wear resistance mechanism of different microstructure under real fraction conditions.As a result,the relationship between the tribological behavior of Fe-Cr-C wear-resisting layer and its microstructure was obtained.The main conclusions of are as follows:The microstructure of Fe-Cr-C deposited layer is composed by primary M₇C₃carbides with different growth directions dispersed in the eutectic austenite and carbide matrix.The difference in macroscopic wear resistance of the deposited layer is caused by the anisotropy of the microscopic mechanical properties of carbides.The main types of friction and wear are adhesive wear and abrasive wear.The breakage and transfer of eutectic carbides and austenite matrix are the main factors of adhesive wear,but cracking and spalling of primary carbides due to stress concentration are the main factors for abrasive wear.The applied load will seriously affect the wear resistance of Fe-Cr-C material.When the stress is low,the carbides can effectively protect the matrix structure and increase the wear resistance of deposited layer.As the applied load increases,the stress concentration of carbides increases.The carbides that grow parallel to the deposited layer preferentially fracture,resulting in increased wear of the deposited layer and reduced wear resistance.