Control of coating thickness of hot-dip metal coating
AssigneeInland Steel Company
InventorsNorman A. Robins, Frank H. Bugajski
Life of this patent
Estimating the term…
Abstract
Objectionable ripple formation in continuous hot-dip coating is avoided by using a single set of blowing nozzles and directing the gas streams downwardly against the strip at an angle between the strip and the center line of the gas stream of from about 0.degree. to about 45.degree., preferably from about 20.degree. to about 40.degree.. The technique is particularly useful at low line speeds of 150 feet per minute or less, especially at high coating weights of 1.5 ounces per square foot or more.
Claims8
In a continuous hot-dip coating line wherein a metal strip is passed through a molten coating bath at a line speed not greater than about 150 feet per minute and is withdrawn vertically from the bath between a pair of gas blowing nozzles for impinging only a single stream of gas against each side of said strip and thereby controlling the coating thickness, the improvement which comprises directing the gas stream from each of said nozzles generally downwardly against the strip at an angle between the strip and the center line of the gas stream of not more than about 40.degree., whereby to eliminate or substantially minimize ripple formation on the surface of the coated product.
Dependencies are inferred from the claim text.