Dual-phase steels

摘要

A process for producing a dual-phase steel in which strip is hot-rolled and cooled to exhibit a substantially bainite structure throughout its cross-section and in which it is subsequently continuously annealed in the two phase ferrite/austenite field and cooled to transform the austenite to martensite. By inter-critically annealing a bainite as opposed to a ferrite/pearlite starting structure in accordance with this invention a very much finer and more uniform distribution of martensite is obtained-this gives rise to superior combinations of ductility and tensile strength.