EBSD Analysis of Graphitized Steel Microstructure after Compression Deformation at Room Temperature

Abstract: Graphitized steel is a very interesting material due to its high wear resistance, excellent cutability, and good properties at cold forming. Graphitized steel (0.43 wt % of C) of ferrite-and-graphite microstructure is plastically deformed by compression at room temperature using a universal testing machine. The microstructures of the deformed samples are analyzed by means of the electron back-scattered diffraction (EBSD). The evolution of microstructure morphology, texture, distribution of kernel average misorientations (KAM), as well as the Taylor factor in the large deformation zone of the compressed samples with different degrees of deformation, are studied. The results show that the graphitized steel has good compressive plastic deformation properties. As the degree of deformation increases, ferrite grains and graphite inclusions line up in a direction perpendicular to the compression axis and gradually transform from an isometric state into a fibrous state. The orientation of ferrite grains in the matrix is ​​obvious, but the orientation of ferrite grains around the graphite inclusions is not obvious, i.e., the number of ferrite grains oriented to 〈100〉 and 〈111〉 in the matrix is ​​much larger than the number of ferrite grains oriented around the graphite inclusions. In addition, the kernel average misorientation and the Taylor factor in the large deformation zone of compressed samples show that the deformation degree of ferrite grains around the graphite inclusions is less than the deformation degree of ferrite grains in the matrix. The reason for this is that the soft inclusion of graphite can reduce the degree of dislocation pile-up. © 2021, Allerton Press, Inc.