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AssigneeArmco Inc.
InventorsCharles Flinchum, Alan F. Gibson, Wayne G. Conley, Gayle P. Fields
Estimating the term…
A finishing method and apparatus for use in conventional hot-dip coating of the type wherein a ferrous base metal strip, having been appropriately pretreated so as to be at or near the proper coating temperature and so as to have its surfaces free of oxides, is cause to pass beneath the surface of a bath of molten coating metal, exiting the bath between conventional finishing rolls. The method comprises the steps of providing an enclosure which overlies at least the coating metal meniscus areas created between the finishing rolls and the strip, and maintaining within the enclosure an inert or non-oxidizing atmosphere to shroud the meniscus areas. The apparatus comprises the above mentioned enclosure with an appropriate system to provide and maintain the inert or non-oxidizing atmosphere therein.
A finishing process for conventional continuous hot-dip, two-side coating of a ferrous base metal strip with a molten coating metal of the type wherein said ferrous base metal strip is caused to enter a bath of said molten coating metal contained in a coating pot, said ferrous base metal strip having been treated to bring it to a coating temperature sufficiently high to prevent casting of said coating metal thereon and low enough to prevent excess coating metal--base metal alloying and to render the surfaces of said strip clean and free of oxide as it passes through said molten coating metal bath, said ferrous base metal strip exiting said bath between a pair of conventional finishing rolls partially submerged in said bath and forming a molten coating metal meniscus to either side of said strip as it passes from between said finishing rolls, a portion of said coating metal at said menisci traveling upwardly with said strip and a portion of said coating metal at said menisci being returned to said bath by said finishing rolls, said finishing process comprising the steps of providing an enclosure which overlies at least said meniscus areas of said finishing rolls and said strip and having an exit slot for said strip, providing a pair of manifolds located to each side of said strip to introduce a non-oxidizing atmosphere into said enclosure and to direct said atmosphere toward said menisci where said portion of said coating metal travels upwardly with said strip and said portion of said coating metal returns to said bath, to shroud said menisci therewith, maintaining said atmosphere at a positive pressure within said enclosure, and withdrawing said strip from said enclosure.
A finishing process for conventional continuous hot-dip, two-side coating of a ferrous base metal strip with a molten coating metal of the type wherein said ferrous base metal strip is caused to enter a bath of said molten coating metal contained in a coating pot, said ferrous base metal strip having been treated to bring it to a coating temperature sufficiently high to prevent casting of said coating metal thereon and low enough to prevent excess coating metal--base metal alloying and to render the surfaces of said strip clean and free of oxide as it passes through said molten coating metal bath, said ferrous base metal strip exiting said bath between a pair of conventional finishing rolls partially submerged in said bath and forming a molten coating metal meniscus to either side of said strip as it passes from between said finishing rolls, a portion of said coating metal at said menisci traveling upwardly with said strip and a portion of said coating metal at said menisci being returned to said bath by said finishing rolls, said finishing process comprising the steps of directing a non-oxidizing atmosphere towards said menisci where said portion of said coating metal travels upwardly with said strip and said portion of said coating metal returns to said bath, and shrouding said menisci with said non-oxidizing atmosphere to provide a uniform smooth coating free of oxide-related defects.
Finishing apparatus for use with a conventional coating line for the hot-dip, two-side coating of a ferrous base metal strip with a molten coating metal, said coating line being of the type having a coating pot, a bath of molten coating metal within said coating pot, means to conduct said ferrous base metal strip through said molten coating metal bath, strip preparation means to bring said ferrous base metal strip to a coating temperature sufficiently high to prevent casting of said coating metal thereon and low enough to prevent excess coating metal-base metal alloying and to render the surfaces of said strip clean and free of oxide as it passes through said molten coating metal bath, at least one pot roll beneath the surface of said bath about which said strip passes and by which said strip is directed upwardly in said bath in a substantially vertical path of travel, and a pair of conventional finishing rolls partially submerged in said bath and forming a molten coating metal meniscus to either side of said strip as it exits said bath and from between said finishing rolls, a portion of said coating metal at said menisci traveling upwardly with said strip and a portion of said coating metal at said menisci being returned to said bath by said finishing rolls, said finishing apparatus comprising an enclosure overlying at least said menisci, said enclosure having an exit slot for said strip, and a pair of manifolds located to each side of said strip to maintain a non-oxidizing atmosphere at a positive pressure within said enclosure and to direct said atmosphere toward said menisci where said portion of said coating metal travels upwardly with said strip and said portion of said coating metal returns to said bath, and to shroud said menisci with said non-oxidizing atmosphere.
Dependencies are inferred from the claim text.