Republic Steel Corporation

Jerry D Thomas

Cecil B Griffith

Dionisyj W Demianczuk

Joseph E Franklin

John K Abraham

Thomas A Wiktorowski

William F Hladio

Leo V Scott

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

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

Effective, low cost sulfide shape control is obtained using in combination titanium and a rare earth metal, e.g., mischmetal, in steels meeting the following specifications: at least 0.020% aluminum, no more than 0.010% nitrogen, no more than 0.025% sulfur, no more than 0.70% manganese, at least 0.020% titanium, and at least 0.020% of at least one rare earth metal. The steels are characterized by sulfide inclusions having a globular and/or fine, short blocky shape.

Control of inclusion morphology in steel

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North Royalton, OH, United States of America

Jerry D Thomas