MANUFACTURING METHOD OF ZINC-PLATED AND ANNEALED STEEL PLATE BY CONTROLLING OF DIRECT-FIRED FURNACE Russian patent published in 2012 - IPC C23C2/02 C23C2/06 C23C2/28 

FIELD: metallurgy.

SUBSTANCE: method involves preparation of steel plate having the following composition, wt %: 0.01 ≤ C ≤ 0.22, 0.50 ≤ Mn ≤ 2.0, 0.5 ≤ Si ≤ 2.0, 0.005 ≤ Al ≤ 2.0, Mo ≤ 0.01, Cr ≤ 1.0, P ≤ 0.02, Ti ≤ 0.20, V ≤ 0.40, Ni ≤ 1.0, Nb ≤ 0.20 and iron and inevitable impurities are the rest; steel plate is oxidised by its being heated from ambient temperature to temperature of 680 to 800°C in direct-fired furnace the atmosphere of which includes air and fuels with air/fuel ratio of 1.0 to 1.2 for formation on its surface of iron oxide layer and at least one internal oxide chosen from group consisting of Si oxide, Mn oxide, Al oxide, complex oxide containing Si and Mn, complex Si and Al oxide, complex Mn and Al oxide and complex oxide containing Si, Mn and Al; reduction of steel plate for reduction of iron oxide layer, zinc-plating by hot dipping method of reduced steel plate and its alloying with formation of zinc-plated and annealed steel plate.

EFFECT: method allows obtaining zinc-plated and annealed steel plate with high mechanical properties, good wetting ability of the surface, good adhesion; thus, non-coated sections are absent and TRIP-effect is maintained.

11 cl, 2 tbl, 2 dwg