Abstract: A twin roll casting system includes a pair of counter-rotating casting rolls having an adjustable nip therebetween, a casting roll controller configured to adjust the nip between the casting rolls in response to control signals; a cast strip sensor measuring a parameter of the cast strip and generating strip measurement signals; and an iterative learning control (ILC) controller receiving the strip measurement signals and providing control signals to the casting roll controller. The ILC controller includes a fault detection algorithm receiving the control signals and the strip measurement signals and generating a fault detection signal indicating when a fault condition is detected and an iterative learning control algorithm to generate the control signals. The fault detection algorithm indicates a fault condition when it detects the control signal exceeding an upper control saturation threshold or the ILC controller operating a state that is not guaranteed as stable.

Abstract: A method and apparatus of continuously casting thin strip by controlling roll crown is provided. The apparatus for continuously casting thin strip by controlling roll crown includes at least two expansion rings positioned within and adjacent a cylindrical tube and spaced within 450 mm of edge portions of the cast strip formed on opposite end portions of casting rolls during a casting campaign. Alternatively or in addition, the apparatus includes at least one expansion ring within the cylindrical tube at a position corresponding to center portions of the cast strip formed on the casting rolls during a casting campaign. Each expansion ring has at least one heating element and an insulating coating thereon and is adapted to increase in radial dimension causing the cylindrical tube to expand changing roll crown of the casting surfaces of the casting rolls and thickness profile of the cast strip during casting.

Abstract: This disclosure concerns methods and apparatus for continuously casting thin strip where one or more expansion rings are positioned within at least one of a pair of casting rolls, and automatically measuring a thickness of the cast strip close to the first side edge of the strip using at least one sensor, and if the thickness measured is too thin, automatically decreasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to contract and increase the thickness of the cast strip during casting, and if the thickness measured indicates that the thickness of the cast strip is too thick, automatically increasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to expand and reduce the thickness of the cast strip during casting.

Abstract: A twin roll casting system where the casting rolls have a nip between the casting rolls, each roller having a circumference and a rotational period. The casting roll controller adjusts the nip between the casting rolls in response to control signals. The sensor measures at least one parameter of the cast strip. The ILC controller receives strip measurement signals from the sensor and provides control signals to the casting roll controller. The ILC controller includes an ILC control algorithm to generate the control signals based on the strip measurement signals and a time delay estimate based on circumference, rotational period, and a length of cast strip between the nip and the sensor to compensate for an elapsed time from the cast strip exiting the nip to being measured by the cast strip sensor.

Abstract: An apparatus for continuous casting metal strip reducing snake eggs comprising a pair of counter rotating casting rolls, each roll less than 800 millimeters in diameter and positioned to form a nip there between through which thin strip can be cast; a metal delivery system disposed above the nip and capable of discharging molten metal to form a casting pool supported on the rolls; a pair of side dam holders and a pair of side dams assembled adjacent each end portion of the rolls, each side dam holder tapered along edge portions to dovetail with an adjacent side dam, and each side dam adapted to confine the casting pool of molten metal supported on casting surfaces of the rolls; an oscillation mechanism adapted to cause lateral oscillation of each side dam and side dam holder at a frequency 2-50 hertz and with an amplitude 100-2000 ?m during a casting campaign.

Abstract: A twin roll casting system where the casting rolls have a nip between the casting rolls, each roller having a circumference and a rotational period. The casting roll controller adjusts the nip between the casting rolls in response to control signals. The sensor measures at least one parameter of the cast strip. The ILC controller receives strip measurement signals from the sensor and provides control signals to the casting roll controller. The ILC controller includes an ILC control algorithm to generate the control signals based on the strip measurement signals and a time delay estimate based on circumference, rotational period, and a length of cast strip between the nip and the sensor to compensate for an elapsed time from the cast strip exiting the nip to being measured by the cast strip sensor.

Abstract: This disclosure concerns methods and apparatus for continuously casting thin strip where one or more expansion rings are positioned within at least one of a pair of casting rolls, and automatically measuring a thickness of the cast strip close to the first side edge of the strip using at least one sensor, and if the thickness measured is too thin, automatically decreasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to contract and increase the thickness of the cast strip during casting, and if the thickness measured indicates that the thickness of the cast strip is too thick, automatically increasing the radial dimension of the expansion ring arranged in close proximity to the first side edge to cause the cylindrical tube to expand and reduce the thickness of the cast strip during casting.

Abstract: A method and apparatus of continuously casting thin strip by controlling roll crown is provided. The apparatus for continuously casting thin strip by controlling roll crown includes at least two expansion rings positioned within and adjacent a cylindrical tube and spaced within 450 mm of edge portions of the cast strip formed on opposite end portions of casting rolls during a casting campaign. Alternatively or in addition, the apparatus includes at least one expansion ring within the cylindrical tube at a position corresponding to center portions of the cast strip formed on the casting rolls during a casting campaign. Each expansion ring has at least one heating element and an insulating coating thereon and is adapted to increase in radial dimension causing the cylindrical tube to expand changing roll crown of the casting surfaces of the casting rolls and thickness profile of the cast strip during casting.

Abstract: Apparatus and method of controlling strip geometry in casting strip having a rolling mill. A target thickness profile is calculated as a function of the measured entry thickness profile of the strip while satisfying profile and flatness parameters. A differential strain feedback from longitudinal strain in the strip is calculated by a control system by comparing the exit thickness profile with the target thickness profile, and a control signal is generated to control a device capable of affecting the geometry of the strip processed by the hot rolling mill. A feed-forward control reference and/or sensitivity vector may also be calculated as a function of the target thickness profile, and used in generating the control signal sent to the control device. The control device may be selected from one or more of the group consisting of a bending controller, gap controller and coolant controller.

Abstract: An apparatus and method for continuously casting thin steel strip includes a pair of counter-rotatable casting rolls laterally positioned to form a nip there between through which thin cast strip can be cast, an actuator capable of moving each casting roll independently toward and away from a given reference location as desired, location sensors capable of sensing the location of the casting rolls relative to the given reference location and producing electrical signals indicative of each casting roll position and a control system capable of receiving the electrical signals and causing the actuator to move the casting rolls into desired position. Force sensors may be provided capable of sensing the forces exerted on the strip and producing electrical signals indicative of the sensed forces, and the control system may be capable of receiving the electrical signals indicative of the sensed forces and causing actuators to vary the position of the casting rolls responsive to the electrical signals as desired.

Abstract: Apparatus and method of controlling strip geometry in casting strip having a rolling mill. A target thickness profile is calculated as a function of the measured entry thickness profile of the strip while satisfying profile and flatness parameters. A differential strain feedback from longitudinal strain in the strip is calculated by a control system by comparing the exit thickness profile with the target thickness profile, and a control signal is generated to control a device capable of affecting the geometry of the strip processed by the hot rolling mill. A feed-forward control reference and/or sensitivity vector may also be calculated as a function of the target thickness profile, and used in generating the control signal sent to the control device. The control device may be selected from one or more of the group consisting of a bending controller, gap controller and coolant controller.

Abstract: 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.