Influence of Spheroidized Cementite on Ferritic Matrix Boundary Characteristics and Mechanical Behavior in Commercial Carbon Steels

This research investigates the effects of accelerated spheroidizing of cementite on the mechanical properties and microstructural characteristics of commercial steel grades (Fe-0.2C, Fe-0.5C, Fe-0.7C wt%), emphasizing the role of cold-rolling reduction followed by stress relief annealing. Utilizing SEM imaging, X-ray diffraction, and EBSD measurements, this study comprehensively examines how variations in carbon content influence hardness, dislocation density, and crystallographic texture orientation. Microhardness measurements reveal a direct relationship with carbon content, yielding values of 28.0±1.0 HRC for DT-1020, 36.0±1.0 HRC for DT-1050, and 39.0±1.0 HRC for DT-1070. Texture analysis through EBSD demonstrates distinct patterns among the grades: DT-1020 displays a dominant (111) texture, DT-1050 exhibits a (101) orientation, and DT-1070 features a more refined (101) texture. Dislocation density analysis further corroborates the impact of carbon content, with DT-1050 presenting the highest density at approximately 7.8×1016 m-2. This detailed exploration elucidates the intricate interplay between carbon content, cementite morphology, and their collective influence on mechanical performance of steel, providing valuable guidance for tailoring steel properties via microstructural control.