NANOSTRUCTURED FERRITE FORMATION IN LOW-CARBON STEEL THROUGH THERMO-MECHANICAL CONTROLLED PROCESSING

摘要

A novel thermomechanical route was developed to produce nanostructured ferrite in a low-carbon steel. Grain refinement was mainly achieved through dynamic recrystallization of the ferrite, which was greatly enhanced by combining dynamic transformation from austenite to ferrite and warm deformation of the martensite. A homogeneous ferrite structure with a mean grain size of 460 nm was obtained only after a total deformation of 60%. The nanostructured ferrite exhibited a high yield strength of 815 MPa and a tensile strength of 832 MPa with a uniform elongation of 10% and total elongation of 28.8%.