Identification of variations or defects in a slab material, made from a continuous casting process
Inventors
Zappulla, Matthew L. S. • Thomas, Brian G.
Assignees
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Publication Number
US-11360039-B2
Publication Date
2022-06-14
Expiration Date
Abstract
Systems, methods, and apparatuses are provided herein that track an integrated deviation of a physical property of a material that corresponds to a variation or defect in the material. In one embodiment, molten steel begins to solidify and move past an instrumented region of a mold. Sensors in the mold can detect a deviation in temperature of the instrumented region of the mold that signifies a variation or defect in the surface of the slab material as it solidifies. The systems, methods, and apparatuses track the integrated temperature deviation to more clearly visualize defects that may otherwise not be detectable by simply observing the temperatures of the mold and slab material in real time.
Core Innovation
The invention relates to a continuous casting defect-detection approach that computes an integrated temperature deviation for locations on a moving slab. It uses dense mold-embedded temperature sensors positioned to detect a local temperature of the mold along the slab travel direction. The approach is intended to reveal defects that are not apparent from raw real-time temperature maps by accumulating temperature deviations over the time the slab location traverses an instrumented region.
The method maps time/position mold temperatures to corresponding slab surface coordinates using casting speed history. It determines a temperature-drop criterion for each mapped location and time based on a defect-free standard temperature profile by computing a temperature drop as a function that uses a minimum of zero relative to the difference between the mold temperature and the standard profile. The accumulated temperature deviation is then obtained by integrating the criterion over the traversal time for that slab location through the instrumented region.
The resulting integrated defect criterion is visualized and used with thresholding to support operator notification and/or process parameter alteration, and for downstream forensic evaluation. The described rationale is that integrating prolonged small temperature drops uncovers casting defects such as longitudinal depression and crack by producing a stronger signal at locations where defects persist over time.
Claims Coverage
The partial content supports four inventive features across the independent claims: moving material past an equipment structure with aligned sensors, accumulating a location/time difference from standard data into a defect criterion, determining an integrated physical property deviation using first and second sensor readings, and determining an integrated temperature deviation using two aligned temperature sensors and a minimum-of-zero temperature-drop model.
Moving a material past equipment structure with aligned sensors detecting local physical properties
A method for detecting defects in a manufacturing process, comprising moving a material past an equipment structure, wherein a plurality of sensors is positioned in said equipment structure and configured to detect a local physical property, and wherein at least two sensors are oriented in a direction of movement of said material.
Accumulating a location/time difference from standard data into a defect criterion
Determining at each location and time in said equipment structure a difference between said data of said local physical properties and standard data corresponding to data where no defects in said material are expected; determining an accumulated difference for each location on said material over a time period based on said difference; and displaying a defect criterion of said accumulated difference at each location on said material for an operator to take corrective action, inspect and downgrade said material at locations having large magnitudes of said accumulated difference, and/or for forensic evaluation to investigate defects.
Providing first and second sensors and determining physical property drops with a minimum of zero
A method for determining an integrated physical property deviation at a single location in a process to manufacture a product, comprising providing a first sensor and a second sensor in an instrumented region of a first material; moving a second material past said instrumented region of said first material; detecting, by said first sensor at a first time, a first physical property of a first location of said first material proximate to a location on said second material; determining, by said electronic device, a minimum of zero and a difference between said first physical property and a first standard physical property to provide a first physical property drop; detecting by said second sensor at a second time a second physical property; determining, by said electronic device, a minimum of zero and a difference between said second physical property and a second standard physical property to provide a second physical property drop; and determining an integrated physical property deviation at said location on said second material based on said first physical property drop, said first time, said second physical property drop, and said second time.
Integrated temperature deviation using two aligned temperature sensors and minimum-of-zero temperature drops
A system for determining an integrated temperature deviation in a manufacturing process, comprising an equipment structure having a surface and an instrumented region positioned proximate to said surface; a material configured to move past said surface in a movement direction; a first temperature sensor and a second temperature sensor positioned in said instrumented region aligned in said movement direction; and an electronic device operably connected to said first temperature sensor and to said second temperature sensor, receiving a first temperature at a first time and determining a minimum of zero and a difference between said first temperature and a first standard temperature to provide a first temperature drop, receiving a second temperature at a second time and determining a minimum of zero and a difference between said second temperature and a second standard temperature to provide a second temperature drop, and determining an integrated temperature deviation at said location on said material based on said first temperature drop, said first time, said second temperature drop, and said second time.
Across the independent claims, the inventive coverage centers on moving material past an instrumented equipment structure with sensors aligned along the movement direction, computing deviations from standard data, limiting temperature or physical-property drops using a minimum of zero relative to standard values, accumulating or integrating these deviations over a time period or between first and second times for each location on the moving material, and using the resulting defect criterion or integrated deviation for operator action and/or forensic evaluation.
Stated Advantages
Integrating accumulated temperature deviations reveals defects that are not apparent from raw real-time temperature maps.
Provides a defect criterion for operator notification and/or process parameter alteration and supports forensic evaluation to investigate defects.
Accumulates prolonged small temperature drops into a stronger defect signal at defect locations.
Enables identification of casting defects such as longitudinal depression and crack.
Documented Applications
Continuous casting defect detection for defects such as longitudinal depression and crack using integrated temperature deviation and threshold-based visualization.
Operator notification and/or process parameter alteration based on the displayed defect criterion, and downstream forensic evaluation to investigate defects.
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