Nucor Corporation

Jay Jon Ondrovic

Katsumi Nakayama

Eric Fulbright

Rama Ballav Mahapatra

Mike Schueren

Richard Britanik

Tino Domanti

Glen Wallace

David W McGaughey

Tim Patterson

Walter N Blejde

David Wayne Mcgaughey

Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 micrometers Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.

Method and apparatus for controlling variable shell thickness in cast strip

An apparatus and method for continuously casting thin steel strip include a pair of counter-rotatable casting rolls in a roll cassette laterally positioned to form a nip there between through which thin cast strip can be cast, adapted to support a casting pool of molten metal on the casting surfaces, an enclosure to support a protective atmosphere immediately beneath the casting rolls in the casting position, and an upper cover positioned below the casting rolls to move between a closed position covering the upper portion of the enclosure maintaining the protective atmosphere in the enclosure in the closed position and a retracted position enabling cast strip to be cast into the enclosure. A scrap receptacle positioned beneath the casting position movable in either direction to a discharge stations. Further, a movable tundish adapted to be transferred from a heating station to the casting position.

Strip casting apparatus for rapid set and change of casting rolls

Apparatus and method for continuously casting metal strip includes a pair of casting rolls having casting surfaces with a center portion, edge portions each having average surface roughness between 3 and 7 Ra, and intermediate portion between each edge portion and the center portion, the center portion average surface roughness between 1.2 and 4.0 times the edge portion surface roughness, and the intermediate portions average surface roughness between that of the edge and center portions. The surface roughness of the center portion is tapered across its width, and may be tapered across its width is in stepped zones. The center portion may have surface roughness varied across the surface to correspond to a desired variation in metal shell thickness across the cast strip. The center portion may be at least 60% of the casting roll width, and each edge portion may be up to 7% of the casting roll width.

A method of continuously casting steel strip includes steps of providing rails positioned beneath a casting position and extending in opposite directions there from to discharge stations, supporting first and second scrap receptacles movable along the rails, engaging a seal between the first scrap receptacle and an enclosure enabling support of a protective atmosphere beneath a pair of casting rolls, disengaging the seal between the first scrap receptacle and the enclosure and moving the first scrap receptacle along the rails in a direction away from the second scrap receptacle to a discharge station, and moving the second scrap receptacle into the casting position and sealingly engaging the second scrap receptacle and the enclosure.

A thin cast strip is formed having at least one microstructure selected from the group consisting of polygonal ferrite, acicular ferrite, Widmanstatten, bainite and martinsite, a surface roughness of less than 1.5 microns Ra and a scale thickness of less than about 10 microns by applying a mixture of water and oil on the work rolls of the hot rolling mill, passing the thin cast strip at a temperature of less than 1100&#xb0; C. through the hot rolling mill while the mixture of oil and water is applied to the work rolls, and shrouding the thin cast strip from the casting rolls through the hot rolling mill in an atmosphere of less than 5% oxygen to form the thin cast strip.

Method for making a low surface roughness cast strip

An apparatus for casting metal strip includes a pair of counter-rotatable casting rolls having casting surfaces laterally positioned to form a nip therebetween through which cast strip can be cast, and on which a casting pool of molten metal can be formed supported on the casting surfaces above the nip, a pair of molten metal delivery nozzles disposed above the nip and capable of discharging molten metal to form the casting pool supported on the casting rolls, a pair of side dams adjacent ends of the pair of casting rolls capable of confining the casting pool, a pair of delivery nozzle actuators capable of positioning the delivery nozzles independently of the side dams and a pair of side dam actuators capable of positioning the side dams independently of the delivery nozzles during casting, and a control system capable of controlling desired distance between the delivery nozzles and the side dams.

Strip casting apparatus with independent delivery nozzle and side dam actuators

Pinch roll apparatus has a pair of pinch rolls, each having a diameter between 300-1500 millimeters, positioned to form a nip through which metal strip can be continuously fed. The pinch rolls are positioned one above the other with the axes of the pinch rolls offset in the direction of travel of the strip, with the upper pinch roll offset positioned between 10 and 130 mm downstream of the direction of travel of the strip through the pinch rolls. A rotational drive counter-rotates the pinch rolls to cause strip to pass through the nip of the pinch rolls. A tilt drive tilts the upper pinch roll by a tilt between 0.5 and 5.0 mm to control steering of the strip passing through the pinch rolls. The steering of the tilt drive may be automatically controlled through a controller actuated by a sensor.

Pinch roll apparatus and method for operating the same

A hot rolling mill and method for operating the hot rolling mill where the shape of the strip is controlled by localized cooling devices positioned at intervals along work rolls in at least three lateral zones, a central and two edge zones, and capable of separately cooling each zone to control the shape of the work rolls in that zone and inhibit the formation of shape defects occurring in the strip being rolled. Five zones may be provided across the work surface of the work rolls so that two intermediate zones can control for quarter buckles. The hot rolling mill has particular application in continuously casting thin strip. The method can be made automatic by sensing downstream of the hot mill the shape of the strip in each zone.

Method and apparatus for controlling strip shape in hot rolling mills

Pinch roll apparatus has a pair of pinch rolls each having a diameter between 300&#x2013;1500 millimeters positioned to form a nip through which metal strip can be continuously fed. The pinch rolls are positioned one above the other with the axes of the pinch rolls offset in the direction of travel of strip, with the upper pinch roll offset positioned between 10 and 130 mm downstream of the direction of travel of the strip through the pinch rolls. A rotational drive counter rotates the pinch rolls to cause strip to pass through the nip of the pinch rolls. A tilt drive tilts the upper pinch rolls by a tilt between 0.5 and 5.0 mm to control steering of the strip passing through the pinch rolls. The steering of the tilt drive may be automatically controlled through a controller actuated by a sensor.

Growing community of inventors

Brownsburg, IN, United States of America

Jay Jon Ondrovic