COLD-ROLLED STEEL SHEET WITH PERFECT PLIABILITY AND METHOD OF ITS PRODUCTION Russian patent published in 2014 - IPC C21D8/02 C21D9/46 C22C38/14 C23C28/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy. To provide for good pliability of sheet at forming under production conditions, cold-rolled sheet is produced which contains the following elements in wt %: C 0.005 or less, Si 0.1 or less, Mn 0.5 or less, P 0.03 or less, S 0.02 or less, N 0.005 or less, Al 0.1 or less, Ti 0.020-0.1 (including 0.020 and 0.1), Fe and incidental impurities making the rest. Wherein TiN particle size does not exceed 0.5 mcm, particle size of Ti sulphide or Ti carbosulphide does not exceed 0.5 mcm while ferrite particle diameter does not exceed 30 mcm. Relationship of X-ray diffraction lines (111//ND) in arbitrarily oriented specimen makes at least 3 and relationship of intensities of X-ray diffraction lines (100)//ND in arbitrarily oriented specimen does not exceed 1. To make the sheet, slab made from steel of aforesaid composition is heated to austenitising temperature and subjected to hot rolled with finish rolling temperature equal to or higher than 890°C. Then, it is wound at 550-720°C, scale is removed, subjected to etching, cold rolling at reduction of at least 50% and annealing at temperature equal to or higher than 700°C.

EFFECT: better pliability at forming under production conditions.

23 cl, 3 tbl, 1 ex