Effect of Hot-rolling Parameters on the Microstructure and Property of Fe-Mn-Al-C Micro-laminated Dual Phase Steels

摘要

In this study, two kinds of micro-laminated dual phase steels with different strength were produced by simple hot rolling and air cooling processes. High carbon and aluminum contents contribute to the high strength in this kind of steel, which has close relationship with the phase ratio and micro-hardness of the ferrite and martensite phases. They were hot rolled at two temperatures (950℃ and 1 100℃) with different reductions (30% and 70%). The mechanical property results reveal that the effects of hot-rolling temperature and reduction on tensile properties are small. The fractography of the samples was examined to explore the relationship between the micro-laminated microstructure and the mechanical properties. It is worth noting that the impact toughness of the rolling plane is enhanced obviously at low hot-rolling temperature with large reduction. The increase of phase interface density along the thickness direction contributes to the ultrahigh impact toughness of rolling plane.