HIGH-STRENGTH HOT-ROLLED STEEL SHEET OF FINE LOCAL WORKING ABILITY AND METHOD OF ITS PRODUCTION Russian patent published in 2016 - IPC C21D8/02 C22C38/00 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy. High-strength hot rolled sheet contains the following elements in wt %: C - 0.07-0.20, Si - 0.001-2.5, Mn - 0.01-4.0, P - 0.001-0.15, S - 0.0005-0.03, Al - 0.001-2.0, N - 0.0005-0.01, O - 0.0005-0.01, iron and unavoidable impurities making the rest. Note here that bainite area fraction in metallographic structure makes 95% or more. Note here that sheet depth central area making 5/8-3/8 of sheet depth from its surface features the mean pole densities of orientation group from {100}<011> to {223}<110> makes 4.0 or less. Note also that pole density of crystal-lattice orientation {332}<113> makes 5.0 or less. Mind that mean-volume diameter of crystal grains in metallographic structure makes 10 mcm or less.

EFFECT: higher local working ability at sufficient steel sheet elongation and strength.

10 cl, 5 tbl, 8 dwg