COLD-ROLLED STEEL SHEET WITH PERFECT PLIABILITY AND METHOD OF ITS PRODUCTION Russian patent published in 2014 - IPC C22C38/06 C21D8/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly to production of cold-rolled steel sheet to be used in motor-car production, various structures, instrument boards, etc. Sheet is made of steel containing in wt %: 0.005-0.030 of C, 0.05 or less of Si, 0.10-0.35 of Mn, 0.025 or less of P, 0.015 or less of S, 0.0045 or less of N, 0.07 or less of Al, Fe and unavoidable impurities making the rest. [%Si]/[%Mn] ratio makes <0.5, diameter of ferrite grain in steel does not exceed 20 mcm while ferrite matrix features at least 50% of cementite precipitation and steel sheet tensile strength does not exceed 325 MPa.

EFFECT: high pliability.

8 cl, 2 tbl, 1 ex