ArcelorMittal S.A.
METHOD FOR PRODUCING A TWIP STEEL SHEET HAVING AN AUSTENITIC MICROSTRUCTURE

Abstract:

A method for the manufacture of a cold rolled, recovered TWIP steel sheet coated with a metallic coating is provided including the following steps: (A) the feeding of a slab having the following composition : 0.1<C<1.2%, 13.0.ltoreq.Mn<25.0%, S.ltoreq.0.030%, P.ltoreq.0.080%, N.ltoreq.0.1%, Si.ltoreq.3.0%, and on a purely optional basis, one or more elements such as Nb.ltoreq.0.5%, B.ltoreq.0.005%, Cr.ltoreq.1.0%, Mo.ltoreq.0.40%, Ni.ltoreq.1.0%, Cu.ltoreq.5.0%, Ti.ltoreq.0.5%, V.ltoreq.2.5%, Al.ltoreq.4.0%, 0.06.ltoreq.Sn.ltoreq.0.2%, the remainder of the composition making up of iron and inevitable impurities resulting from elaboration; (B) Reheating such slab and hot rolling it; (C) A coiling step; (D) A first cold-rolling; (E) A recrystallization annealing; (F) A second cold-rolling; and (G) A recovery heat treatment performed by hot-dip coating.