Abstract: A method and apparatus for continuously treating a strip of hot dip-galvanized steel. The method comprises the steps of rapidly reheating the strip to a predetermined temperature between 460.degree. C. and 600.degree. C., with a heating flux greater than 180 kWatts per meter squared based for each face of the strip; maintaining the strip at a substantially constant temperature for a predetermined period of time lasting between 10 and 30 seconds; and subsequently cooling the strip rapidly to a temperature below 420.degree. C., using a cooling flux of a magnitude greater than 100 kWatts per meter squared for each face of the strip. The step of rapidly reheating is performed following a drying operation conducted on the strip as it exits from a zinc bath.
Type:
Grant
Filed:
August 21, 1995
Date of Patent:
May 13, 1997
Assignees:
Centre de Recherches Metallurgiques-Centrum Voor Research In de Metallurgie, Cockerill Sambre S.A., Hoogovens Groep BV, N.V. Sidmar
Inventors:
Stephan Wilmotte, Michel Dubois, Erik Van Perlstein, Simon Vandenbruaene, Michel Beguin
Abstract: A method for metallothermally reheating a liquid steel bath in a metallurgical container into which a metal fuel is placed and oxidizing and agitating gases are injected under its surface. A controllable flow resulting from the injection of agitating gas is generated in the bath by means of a device which is separate from the oxidizing gas injection device, and the metal fuel is inserted into said flow so that it comes into contact with said oxidizing gas.
Abstract: This invention provides a process and an apparatus for baking an organic coating which has been applied to a substrate. Such coated substrates are conventionally baked in a furnace using a mixture of combustion gas and air. This process in uneconomical in terms of energy consumption and also involves cleansing of used gases before they can be discharged into the atmosphere. The present invention provides a rapid process for baking such coatings in an inert gas atmosphere by means of short-wavelength infra-red rays. Coatings are heated in such a penetrating manner than they are baked at the substrate/coating interface and this prevents the formation of swellings.