Republic Steel Corporation

Cecil B Griffith

Robert Sobolewski

Alexander A Zavaras

Jerry D Thomas

Dionisyj W Demianczuk

Joseph E Franklin

John K Abraham

Robert E Ryan

Thomas A Wiktorowski

Michael J George

High strength, low alloy steel is produced, preferably as a hot rolled article (e.g. strip), to have a rimmed skin of essentially ferrite while having a main body or core which is aluminum-killed and comprises, for superior mechanical properties including yield strength, a suitable quantity of columbium and/or vanadium. The carbon, manganese and sulfur contents of the base metal, which provides the skin and plus the addition, the core, are preferably limited to provide special results as low alloy steel and also, by the same limitations, to provide auto sulfide shape control and thus to avoid unwanted directionality regarding toughness and bendability. The steel is made by pouring a mold 80-95% full of the base composition, then allowing the steel to rim for several minutes, and after a shell has solidified, continuing to pour while adding Al and Cb or V to the teemed stream, thereby providing an ingot with the above killed core, which can be hot reduced as desired.

High strength, low alloy steel with improved surface and mechanical

In continuous casting of metal in an open-ended mold through which the metal is advanced in a first direction while undergoing peripheral solidification, and to which molten metal is supplied by a shroud that opens beneath the metal level, the provision of electromagnetically produced metal circulation in the mold causing laminar flow of molten metal, in a second direction opposite to the first direction and at a rate not above 35 cm./sec., along the solid-liquid interface within the mold for preventing entrapment of inclusions at the interface.

Process and apparatus for the continuous casting of metal using

A vessel, particularly a ladle, and method for mixing molten metal. The vessel is adapted to be used in an upright position and has bottom openings, including at least one first opening for the introduction of gas under pressure to stir the contents, and a second opening for discharging contents. A porous plug prevents metal from flowing through each first opening and a stopper controls discharge of metal through the second opening. The inside bottom surface of the vessel is sloped downwardly toward the first opening or openings and the entrance to the second opening is at a level above all first openings when the vessel is upright. The porous plug or plugs may be recessed with respect to the inside bottom surface. Any material that settles from the molten metal will tend to collect directly above a porous plug and become entrained in the stirred metal upon the introduction of gas.

Gas stirrer

In continuous casting of metal in an open-ended mold through which the metal is advanced in a first direction while undergoing peripheral solidification, and to which molten metal is supplied by a shroud that opens beneath the metal level, use of a shroud having an axial nozzle and terminating in a well beyond the nozzle, with lateral discharge ports between the well and the nozzle oriented to discharge the supplied metal at an obtuse angle to the first direction, assists in reducing the incidence of entrapped inclusions. Injection of inert gas into the flow of molten metal within the shroud promotes transport of inclusions in the second direction within the mold. The shroud and/or inert gas injection may be employed in combination with the provision of electromagnetically produced metal circulation in the mold causing flow of molten metal, in a second direction opposite to the first direction, along the solid-liquid interface within the mold for preventing entrapment of inclusions at the interface.

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North Royalton, OH, United States of America

Cecil B Griffith