ArcelorMittal S.A.
COLD ROLLED AND ANNEALED STEEL SHEET, METHOD OF PRODUCTION THEREOF AND USE OF SUCH STEEL TO PRODUCE VEHICLE PARTS

Abstract:

A cold rolled and annealed steel sheet including by weight: 0.6<C<1.3%, 15.ltoreq.Mn<35%, 6.ltoreq.Al<15%, Si.ltoreq.2.40%, S.ltoreq.0.03%, P.ltoreq.0.1%, N.ltoreq.0.1%, possibly one or more optional elements chosen among Ni, Cr and Cu in an individual amount of up to 3% and possibly one or more elements chosen among B, Ta, Zr, Nb, V, Ti, Mo, and W in a cumulated amount of up to 2.0%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, the microstructure of the sheet including of ordered ferrite between 1% and 10%, optionally of up to 10% of kappa carbides, the remainder being made of austenite, and, the density of the steel sheet being equal or below 7.2 and the FWHM for the austenite matrix is between 0.700 and 1.100.