Improving Ductility in Dual-Phase Steel by Cold Rolling and Intercritical Annealing

Abstract

Dual-phase steels offer huge potential to provide a cost-effective solution in the automobile industry to fulfill the demand for high strength with formability. The desirable strength is achieved by increasing geometrically necessary boundaries and ferrite grain refinement but not by increasing martensite fraction. The major challenge is to improve the ductility and formability, without compromising its strength. In this work, cold rolling reductions to ∼84% was given to hot rolled annealed steel, followed by intercritical annealing and water quenching. Tensile tests, Optical microscopy, Electron Back Scattered Diffraction and X-Ray characterizations were carried out. The improvement in strength and ductility were correlated with microstructure and texture.