HIGH-FORMABILITY SHEET STEEL FOR MAKING LIGHT-WEIGHT STRUCTURAL PARTS AND A METHOD OF MANUFACTURING Russian patent published in 2020 - IPC C22C38/14 C22C38/38 C22C38/32 C22C38/58 C22C38/54 B22D11/06 B21B1/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely, to production of sheet steels or structural parts used in automotive industry. Sheet steel has chemical composition, wt%: 0.010≤C≤0.080; 0.06≤Mn≤3; Si≤1.5; 0.005≤Al≤1.5; S≤0.030; P≤0.040; Ti and B in quantities meeting the conditions: 3.2≤Ti≤7.5 and (0.45×Ti)–1.35≤B≤(0.45×Ti)–0.43; optionally Ni≤1; Mo≤1; Cr≤3; Nb≤0.1 and V≤0.1; balance is iron and unavoidable impurities. Sheet steel has a microstructure consisting of ferrite, at most 10 % of austenite and emissions, wherein emissions include eutectic release of TiB₂. Volumetric fraction concentration of TiB₂ emissions relative to the total microstructure is at least 9 %, and the fraction of TiB₂ emissions, characterized by the surface area of less than 8 mcm², is at least 96 %.

EFFECT: steel has high specific tensile modulus combined with high deformability, particularly high plasticity and high viscosity.

27 cl, 15 dwg, 8 tbl