| 摘要 |
FIELD: metallurgy. ^ SUBSTANCE: method involves annealing of steel plate in annealing furnace having front heating zone, rear heating zone, exposure zone and cooling zone in steel plate movement direction, and application of coating by means of hot dipping method of steel plate to electrolytic bath located after annealing furnace at continuous supply of steel plate from annealing furnace to electrolytic bath of hot dipping. Heating and exposure of steel plate is performed at temperature of steel plate of at least 300C or more by applying indirect heating; at that, in front heating zone, rear heating zone, exposure zone and cooling zone there formed is gas medium consisting of hydrogen in quantity of 1 to 10 vol. % and nitrogen and inevitable impurities are the rest, and dew points of front heating zone are brought to the value which is less than -25C, rear heating zone and exposure zone to the value of -30 to 0C, and cooling zone - to the value of below -25C, and annealing is performed at maximum steel plate temperature during heating in front heating zone of 550 to 750C. ^ EFFECT: invention allows preventing formation of surface metallic iron oxides in relatively low temperature area and inducing internal Si or Mn oxidation, which allows avoiding deterioration of covering steel plate capability and deceleration of alloying. ^ 8 cl, 2 dwg, 2 tbl, 1 ex |
