Nucor Corporation

Walter N Blejde

Rama Ballav Mahapatra

Lazar Strezov

Mark Schlichting

Kannappar Mukunthan

Rama Mahapatra

Mike Schueren

Joel D Sommer

David John Sosinsky

Christopher Ronald Killmore

James Williams

Harold Roland Kaul

Eugene B Pretorius

Neera Jain Sundaram

Frank Barbaro

Ivan David Parkes

Philip John Renwick

Jianqi Ruan

Andrew Phillips

Scott Story

Dave Sosinsky

Harold Bradley Rees

Jay Jon Ondrovic

Peter Andrew Woodberry

Brian Bowman

Robert Nooning, Jr

James W Watson

W Kent Cooper

George T C Chiu

James Leacock McIntosh

Paul Kelly

Malcolm McDonald

Jim Edwards

Andrew Glutz

Steven Leonard Wigman

Steve Leonard Wigman

Michael A Schueren

George Tc Chiu

Brian D White

Rama Mahaptra

Clay A Gross

A twin roll casting system comprises a pair of counter-rotating casting rolls having a nip between the casting rolls and capable of delivering cast strip downwardly from the nip; a casting roll controller configured to adjust at least one process control setpoint between the casting rolls in response to control signals; a cast strip sensor capable of measuring at least one parameter of the cast strip; and a controller coupled to the cast strip sensor to receive cast strip measurement signals from the cast strip sensor and coupled to the casting roll controller to provide control signals to the casting roll controller. The controller comprises a reinforcement learning (RL) Agent, the RL Agent generating control signals for the casting roll controller in response to a reward function having a first term rewarding emulating human operation of the process control setpoint and a second term rewarding a short set-up time.

Application of a learning agent to achieve autonomous operation of a twin roll casting machine

A twin roll casting system includes a pair of counter-rotating casting rolls, a casting roll controller is configured to receive a plant input comprising at least one process control setpoint for the casting rolls. A cast strip sensor measures at least one parameter of the cast strip. A feedback controller receives measurement signals from the cast strip sensor. The feedback controller is a data-driven model including a database of state-input pairs; and executes the following steps at each time step: measure a state-input similarity between a new state observation and samples, assign a weight to each consequent output of samples based on the measured state input similarity, and sum the weighted outputs and predict an output of a new state observation. The feedback controller is configured to provide the control setpoint to the casting roll controller based on the predicted output of the new state observation.

Training-free data-driven method for input-output modeling of complex process

This application discloses thin metal strips and methods of making thin metal strip. Particular embodiments of such methods include cooling the thin metal strip to a temperature equal to or less than a bainite or a martensite start transformation temperature Bor Mto thereby form bainite and/or martensite, respectively, within the thin metal strip, reheating the thin metal strip to a reheat temperature equal to or greater than transformation temperature Acand holding the thin metal strip at the reheat temperature for at least 2 seconds and thereby forming austenite within the thin metal strip with at least 75% of austenite grains having a grain size equal to or less than 15 &#x3bc;m, and rapidly recooling the thin metal strip to a temperature equal to or less than the martensite start transformation temperature Mand thereby providing finer martensite within the thin metal strip from a finer prior austenite.

Thermal cycling for austenite grain refinement

A method of continuously casting thin strip dynamically controlling roll casting surface configuration by controlling the temperature of water flowing through the longitudinal water flow passages in a cylindrical tube thickness of no more than 80 millimeters of counter rotated casting rolls, and varying the speed of the casting rolls with attenuation of the ends of the casting rolls with a casting roll drive system responsive to electrical signals received from sensors during a casting campaign.

Method for casting metal strip with dynamic crown control

A method of continuously casting thin strip dynamically controlling roll casting surface configuation by controlling the temperature of water flowing through the longitudinal water flow passages in a cyclindrical tube thickness of no more than 80 millimeters of counter rotated casting rolls, and varying the speed of the casting rolls with attenuation of the ends of the casting rolls with a casting roll drive system responsive to electrical signals received from sensors during a casting campaign.

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

During continuously casting metal strip, delivering molten metal supported on the casting surfaces of the casting rolls, and counter rotating the casting rolls to form metal shells on the casting surfaces brought together at the nip to deliver cast strip downwardly with a controlled amount of mushy material between the metal shells, determining at a reference location downstream from the nip a target temperature for the cast strip corresponding to a desired amount of mushy material between the metal shells of the cast strip, sensing the temperature of the cast strip cast downstream from the nip at the reference location and producing a sensor signal corresponding to the sensed temperature, and causing an actuator to vary the gap at the nip between the casting rolls in response to the sensor signal received from the sensor and processed to determine the temperature difference between the sensed temperature and the target temperature.

Method and apparatus for controlling strip temperature rebound in cast strip

A method of continuously casting metal strip may include assembling a pair of casting rolls having casting surfaces laterally positioned to form a nip therebetween through which thin cast strip may be cast, a metal supply system capable of delivering molten steel above the nip, the casting rolls having a crown shape so that edge portions of the cast strip within 50 millimeters of edge of the cast strip have a higher temperature than the cast strip in center portions of the strip width and controlled edging up, forming a casting pool of molten steel supported on the casting surfaces above the nip and controlling side dams adjacent the ends of the nip to confine the casting pool, and forming a cast strip such that the edge portions of the cast strip within 50 millimeters of each edge of the cast strip is of a higher temperature than the strip in the center portions of the strip width.

Strip casting method for controlling edge quality and apparatus therefor

A side dam for use in a continuous twin roll caster system includes a body of refractory material having opposed outer surfaces with one outer surface adapted to contact molten metal and casting rolls in a continuous twin roll caster system and retain molten metal, and an opposite outer surface having fastening portions of refractory material adapted to attach the side dam to a side dam holder to hold the side dam in place during casting; an aperture in the outer surface of the body positioned adjacent a nip of the continuous twin roll caster system and adapted to receive a side dam insert; and a side dam insert of a second refractory material harder than the refractory material of the body having a first surface adapted to contact molten metal and form with the outer surface of the body the outer surface of the side dam.

Side dam with insert

A method of producing cast steel strip having low surface roughness and low porosity by casting with molten steel having a total oxygen content of at least about 70 ppm and a free oxygen content between 20 and 60 ppm, and a temperature that allows a majority of any oxide inclusions to be in a liquidus state. The total oxygen content may be at least 100 ppm and the free oxygen content between 30 and 50 ppm. The steel strip produced by the method may have a per unit area density of at least about 120 oxide inclusions per square millimeter to a depth of about 2 microns from the strip surface.

Casting steel strip with low surface roughness and low porosity

A steel product with a high austenite grain coarsening temperature having less than 0.4% carbon, less than 0.06% aluminium, less than 0.01% titanium, less than 0.01% niobium, and less than 0.02% vanadium by weight, and having fine oxide particles containing silicon and iron distributed through the steel microstructure having an average particle size less than 50 nanometers and may be between 5 and 30 nanometers. The steel product may have fine oxide particles distributed through the microstructure capable of restricting ferrite recrystallization for strain levels up to at least 10.0%, for temperatures up to 750&#xb0; C. with holding times up to 20 minutes. The steel product may be made by continuous casting of steel strip introduced between the casting rolls to form a casting pool of molten carbon steel having a total oxygen content of at least 70 ppm usually less than 250 ppm, and a free oxygen content 20 and 60 ppm, counter rotating the casting rolls.

Steel product with a high austenite grain coarsening temperature

A method of continuously casting metal strip for a twin roll caster may include steps of sensing images of a casting pool in the casting area indicative of the casting pool depth, displaying the sensed images to an operator, and controlling a flow of molten metal from a metal supply system into the casting pool responsive to the sensed images indicative of the casting pool depth. The method may include producing separate electrical signals corresponding to the sensed images and controlling the flow of molten metal from the metal supply system into the casting pool responsive to one or more of the electrical signals. The electrical signals may be processed to determine the casting pool depth in each of the plurality of locations and the casting pool depth displayed to the operator. One or a combination of the electrical signals may be selected for providing a determined casting pool depth, and the flow of molten metal may be controlled responsive to the determined casting pool depth. The determined casting pool depth may be an average of casting pool depths from the selected electrical signals.

Production of thin steel strip

A metal strip casting apparatus and a method of casting continuous metal strip includes assembling a pair of counter-rotatable casting rolls having casting surfaces positioned laterally forming a nip between for casting, and delivering molten metal through a delivery nozzle disposed above the nip capable to form a casting pool supported on the casting rolls. The delivery nozzle comprises segments each having elongate nozzle body with longitudinally extending side walls, end walls and a bottom part to form an inner trough, a nozzle insert disposed above bottom portions of the inner trough of each segment and supported relative to the nozzle body through which incoming molten metal may be delivered to the inner trough of each segment of the delivery nozzle, and the elongate nozzle body of each segment having passageways in fluid communication with the inner trough and outlet openings capable of discharging molten metal from the nozzle body outwardly into the casting pool.

Casting delivery nozzle with insert

A method of and apparatus for continuous casting of thin cast strip including removing oxides from the casting surface of each casting roll by contacting the casting surface of each casting roll with a rotating brush between the nip and the casting area, determining the temperature in segments along the casting roll surfaces or across the cast strip adjacent the nip, and delivering gas adjacent the casting surface between the rotating cleaning brush and the casting area regulated in segments corresponding to the determined temperature in the segment to control the quality of the strip produced. The gas delivery adjacent the casting surface between the rotating brush and the casting area may be done in at least five segments along the casting roll, and the temperature determination step may be done in a continuum such as by a scanning pyrometer. The temperature determination of the cast strip may be done between 0.2 and 1 meter from the nip.

Method and apparatus for localized control of heat flux in thin cast strip

A method of controlling in a twin roll strip caster the thickness of as-cast strip by determining and operating at a target depth of the casting pool and a target speed of the casting rolls. The as-cast strip may be cast to a customer-specified thickness or may be subsequently rolled to a customer-specified thickness.

Growing community of inventors

Brownsburg, IN, United States of America

Walter N Blejde