STEEL AND ITEM MADE FROM IT (VERSIONS) Russian patent published in 2010 - IPC C22C38/06 C22C38/14 C22C38/12 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, silica, manganese, phosphorus, aluminium, nitrogen, iron and inevitable impurities at the following component ratio, wt %: carbon 0.025 - 0.10, silica not more than 0.30, manganese 0.41 - 0.70, phosphorus 0.04 - 0.12, aluminium 0.01 - 0.08, nitrogen not more than 0.009, iron and inevitable impurities - the rest. Steel can also contain titanium or niobium or vanadium in quantity of 0.01-0.03 wt %, as well as boron in quantity of 0.0008-0.003. Carbon content is related to the required strength class by the following dependence: [C]≥(0.0005-K_point - 0.085), %, where [C] - steel carbon content, %, 0.0005 and 0.085 - empirical coefficients, %, K_point - non-dimensional parametre numerically equal to the required minimum yield point.

EFFECT: rolled products have increased strength characteristics and high formability and reduced production costs.

9 cl, 3 tbl, 1 ex