HIGH-STRENGTH COLD-ROLLED STEEL PLATE WITH EXCELLENT ABILITY FOR DEEP DRAWING, AND ITS MANUFACTURING METHOD Russian patent published in 2014 - IPC C22C38/14 C22C38/12 C21D8/04 

FIELD: metallurgy.

SUBSTANCE: plate is made from steel containing the following, wt %: C 0.005 or less, Si 0.1-0.8, Mn 1.0-2.5, P 0.1 or less, S 0.02 or less, N 0.0035 or less, Al: 0.1 or less, at least one type of the element chosen from Ti 0.005-0.05 and Nb 0.01-0.08, and Fe and inevitable impurities are the rest. Ferrite grain diameter is at least 7 mcm. Ratio of ferrite grain length in rolling direction to ferrite grain length in plate thickness direction is 2.5 or less. A fraction of a high-angle boundary of the grain, at which disorientation of crystal between two adjacent crystals and a boundary between them is at least 15° is 50% and more throughout the ferrite grain boundary.

EFFECT: plates have high strength at high deep drawing.

16 cl, 3 tbl, 1 ex