Characterization of the as-received state of a SA 508 Gr.3 Cl.1 steel by backscattered electrons in a scanning electron microscope

Abstract

In this work, metallographic characterization techniques such as optical microscopy and scanning electron microscopy with backscattered and secondary electrons detection were employed to analyze the as-received metallurgical state of a SA 508 Gr.3 Cl.1 steel. Two distinct regions were observed within the microstructure, referred to as the segregated zone and the matrix zone, characterized by differences in size, shape, and density of the precipitated second phases. The so-called segregated zone was associated with the chemical macrosegregation produced during the steel casting process. The use of backscattered electron signals allowed for the identification of distinct crystal orientations within the matrix zone and the presence of carbide clusters within the segregated zone. These results were further complemented by an analysis of the X-ray diffraction pattern by using the Rietveld refinement method.