ANNEALED LAYER OF GALVANIC COATING, AND STEEL PLATE WITH SUCH COATING, AND METHOD OF ITS PRODUCING

摘要

FIELD: metallurgy.SUBSTANCE: in the coating an average content of Fe is in the range from 8.0 to 12.0%, wherein the absolute difference ΔFe between Fe content at 1/8 of the thickness and Fe content at 7/8 of the thickness of the coating, measured from the surface of border between the surface and the steel plate to the external surface of the coating is in the range from 0.0 to 3.0%. Upon producing of the suggested coating after the completion of hot dip galvanisation and alloying treatment the diffusion treatment is performed inside the annealed galvanic coating, wherein the galvanised with annealing steel plate is held at a temperature in the range from 250 to 450°C, and the galvanised with annealing steel plate is treated with single or multiple bending-unbending in this temperature range for Fe diffusion in the annealed galvanic coating.EFFECT: invention relates to the annealed galvanic coating made on the surface of a high-strength base steel plate, and having an improved strength of adhesion with the surface of the said plate.12 cl, 2 dwg, 14 tbl