The Impact of Retained Austenite on the Mechanical Properties of Bainitic and Dual Phase Steels

Abstract This paper presents the microstructural changes and mechanical properties of carbide-free bainitic steel subjected to various heat treatment processes compares these results with similarly treated ferritic–pearlitic steel. A key feature investigated steel, which is common among others described in literature, that Si content developed was >1 wt.% avoid carbide precipitation retained austenite during transformation. The phase identification before after conditions carried out based on observations x-ray diffraction. Hardness measurements tensile tests were conducted determine materials. In addition, following tests, fracture surfaces both types steels analyzed. Changing transformation temperature generated distinct volume fractions different values strength properties. examined strongly influenced by morphological features constituents. It worth noting characterized a high ultimate (1250 MPa) combined total elongation 18% austenitizing continuous cooling. chemical composition designed obtain optimal microstructure hot deformation followed natural cooling still air. Extensive using isothermal bainite understand relationships between resulting microstructures, properties, characteristics. indicated relationship sample obtained at 400 °C. However, it should be noted differed little from condition