Microstructural and Thermomechanical Characterization of the Bassar Remelted Steel

This article presents the microstructural and thermomechanical study of the Bassar remetlted steel obtained from melting Bassar as-smelted steel. Bassar as-smelted Steel is steel made by direct reduction of Bandjeli iron ore in a natural draught furnace. Bandjeli village is located in the Bassar Region in the Republic of Togo (West Africa). The Bassar remelted steel was obtained by melting at 1370°C of Bassar as-smelted Steel in a high frequency furnace to eliminate inclusions and pores contained in the Bassar as-smelted Steel. The microstructural and mechanical analyses show that the Bassar remelted steel is homogeneous and contains no defects compared to as-smelted steel. The microstructure of the remelted Steel is formed of ferritic grain whose average size is more than 0.5 mm. Some precipitates are observed in grain and grain boundaries. Heat treatment shows that the average grain size increases as the annealing temperature increases. For the sample annealed at 600°C for one hour, its tensile strength is 338 MPa and the strain rate is 20%. The mechanical properties of the Bassar remelted steel decrease after annealed at 800°C and 950°C for one hour.