AUTOPLATE COLD-ROLLED STEEL FOR DEEP FORMING Russian patent published in 2011 - IPC C22C38/50 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, manganese, silicon, sulphur, phosphorus, chrome, nickel, copper, nitrogen, aluminium, titanium, niobium and iron at the following component ratio, wt %: carbon of more than 0.007 - 0.009, manganese 0.10 ÷ 0.14, silicon ≤ 0.02, sulphur ≤ 0.013, phosphorus ≤ 0.012, chrome ≤ 0.02, nickel ≤ 0.03, copper ≤ 0.04, nitrogen ≤ 0.006, aluminium 0.03÷0.06, titanium (2.4S+3.43N) ÷ (2.4S+3.43N)+0.03, niobium 7.75C÷7.75C+0.02, iron is the rest, where (S), (N), (C) - content of sulphur, nitrogen and carbon in steel. It has ultimate strength σ_u=270÷350 N/mm², yield strength δ_τ≤180 N/mm², relative elongation σ₄≥38 %, plastic anisotropy factor r₉₀≥1.8, strain strengthening parameter n₉₀≥0.22.

EFFECT: improving steel application properties.

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