COLD-ROLLED STEEL FOR DEEP DRAWING Russian patent published in 2004 - IPC

FIELD: metallurgy.

SUBSTANCE: invention relates to composition of cold-rolled steel designating for making articles with complex configuration being mainly for car articles, among them, with protective covers. The claimed cold-rolled steel for deep drawing comprises components taken in the following ratio, wt.-%: carbon, 0.001-0.006; silicon, 0.002-0.020; manganese, 0.07-0.30; phosphorus, 0.005-0.020; sulfur, 0.005-0.010; aluminum, 0.015-0.050; nitrogen, 0.002-0.006; titanium, 0.02-0.08; niobium, 0.005-0.060; oxygen, 0.001-0.005; iron and inevitable impurities, the balance. The total content of aluminum and titanium is 0.07-0.12 wt.-% and the ratio of aluminum content to oxygen content is less 5.0. Minimal titanium content is calculated from the following ratio: (Ti)_min = 3.43 (N) + 2.4 (S) wherein (Ti), (N) and (S) mean the content of titanium, nitrogen and sulfur, respectively, in wt.-%. Optimal niobium content in steel is determined from the following ratio: 0.005% ≤ (Nb) ≤ 7.75 (C) or 7.75 (C) < (Nb) ≤ 0.06% wherein (C) and (Nb) mean the content of carbon and niobium, respectively, in wt.-%. Invention provides enhancing stamping capacity of steel being independently of regimen of thermal treatment and applying the protective cover, and enhancing the corrosion resistance also.

EFFECT: valuable properties of steel.

3 cl, 1 tbl, 1 ex