METHOD OF MAKING GALVANIZED AND ANNEALED STEEL SHEETS Russian patent published in 2020 - IPC C23C2/02 C23C2/06 C23C2/28 C23C2/40 C23C28/02 C21D9/46 

FIELD: technological processes.

SUBSTANCE: group of inventions relates to a method of making galvanized and annealed steel. Method includes the following consecutive steps: A) production of sheet steel with applied preliminary coating in form of a first coating containing iron and nickel, wherein sheet steel is characterized by following chemical composition, wt. %: 0.10 < C < 0.40; 1.5 < Mn < 3.0; 0.7 < Si < 2.0; 0.05 < Al < 1.0; 0.75 < (Si + Al) < 3.0 and optionally one or more elements, such as Nb ≤ 0.5; B ≤ 0.005; Cr ≤ 1.0; Mo ≤ 0.50; Ni ≤ 1.0; Ti ≤ 0.5; balance - iron and unavoidable impurities; B) heat treatment of sheet steel with applied coating at temperature in range between 600 and 1000°C; C) applying to the sheet steel obtained at stage B) of the second zinc-based coating by immersion into the melt; and D) alloying treatment to produce galvanized and annealed steel.

EFFECT: invention ensures production of galvanized and annealed sheet steel, which is not associated with problems associated with liquid-metal embrittlement after molding and / or welding.

25 cl, 3 tbl