COLD-ROLLED AND ANNEALED STEEL SHEET, METHOD OF ITS MANUFACTURING AND USE OF SUCH STEEL FOR PRODUCTION OF VEHICLE PARTS Russian patent published in 2023 - IPC C22C38/04 C22C38/06 C22C38/38 C22C38/58 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to a cold-rolled and annealed steel sheet used for the manufacture of safety elements or structural elements of a vehicle. The steel sheet contains, wt.%: 0.6<C<1.3, 15≤Mn<35, 6≤Al<15, Si≤2.40, S≤0.03, P≤0.1, N≤0.1, if necessary, at least one element selected from Ni, Cr and Cu individually up to 3%, and, if necessary, at least one element selected from B, Ta, Zr, Nb, V, Ti, Mo and W in a total amount of up to 2.0%, the rest is iron and inevitable impurities. The microstructure of the sheet consists of ordered ferrite 1-10%, optionally up to 10% kappa carbides, the rest consists of austenite. The density of the steel sheet is equal to or lower than 7.2, and FWHM value of the austenitic matrix is 0.700°-1.100°, where FWHM refers to the index of the deformed state of austenite estimated by X-ray diffraction by measuring the full width at half maximum (FWHM) of the diffraction peak corresponding to the {311} planes.

EFFECT: obtaining a steel sheet with the required level of mechanical properties.

24 cl, 4 tbl