ArcelorMittal S.A.
Low-density hot-or cold-rolled steel, method for implementing same and use thereof

Abstract:

A rolled steel sheet is provided. The rolled steel sheet has a mechanical strength greater than or equal to 600 MPa and an elongation at fracture that is greater than or equal to 20%. A a method for its fabrication is also provided. The chemical composition of the steel sheet includes 0.10.ltoreq.C.ltoreq.0.30%, 6.0.ltoreq.Mn.ltoreq.15.0%, 6.0.ltoreq.Al.ltoreq.15.0%, and optionally one or more elements selected from among: Si.ltoreq.2.0%, Ti.ltoreq.0.2%, V.ltoreq.0.6% and Nb.ltoreq.0.3%. The remainder of the composition includes iron and the unavoidable impurities resulting from processing. The ratio of the weight of manganese to the weight of aluminum is such that > ##EQU00001## The microstructure of the sheet includes ferrite, austenite and up to 5% Kappa precipitates in area fraction.