Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.

Abstract: 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 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.

Abstract: 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 100 ppm and a temperature that allows a majority of any oxide inclusions to be in a liquidus state. 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.

Abstract: A model-based strategy is provided for determining casting roll operating temperature in a continuous thin strip casting process. A first temperature sensor produces a first temperature signal indicative of the temperature of cooling liquid supplied to the casting rolls and a second temperature sensor produces a second temperature signal indicative of the temperature of cooling liquid temperature exiting the casting rolls. A computer determines a heat flux value as a function of the first and second temperature signals, and computes the operating temperature of the casting rolls as a function of the heat flux value, the second temperature signal and a number of constants defined by fixed-valued operating parameters of the continuous thin strip casting process. A control strategy is also provided to modify one or more operating parameters of the continuous thin strip casting process as a function of the casting roll temperature.

Abstract: A cast carbon steel strip is prepared by continuously casting in a twin roll caster and cooling to transform the strip from austenite to ferrite at a temperature range between 400° C. and 850° C. at a cooling rate of not more than about 100° C./sec, such that the strip has a yield strength of greater than 450 MPa. The cast strip before cooling is passed through a hot rolling mill to reduce the thickness of strip by at least 15% and up to 50%.

Abstract: A plain carbon steel strip is continuously cast in a twin roll caster and passes to a run out table on which it is subjected to accelerated cooling by means of cooling headers whereby it is cooled to transform the strip from austenite to ferrite at a temperature range between 850° C. and 400° C. at a cooling rate of not less than 90° C./sec, such that the strip has a yield strength of greater than 450 MPa. The strip after casting and before cooling is passed through a hot rolling mill to reduce the thickness of strip by at least 15% and up to 50%.

Abstract: A model-based strategy is provided for determining casting roll operating temperature in a continuous thin strip casting process. A first temperature sensor produces a first temperature signal indicative of the temperature of cooling liquid supplied to the casting rolls and a second temperature sensor produces a second temperature signal indicative of the temperature of cooling liquid temperature exiting the casting rolls. A computer determines a heat flux value as a function of the first and second temperature signals, and computes the operating temperature of the casting rolls as a function of the heat flux value, the second temperature signal and a number of constants defined by fixed-valued operating parameters of the continuous thin strip casting process. A control strategy is also provided to modify one or more operating parameters of the continuous thin strip casting process as a function of the casting roll temperature.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip of no more than 5 mm thickness having austenite grains that are coarse grains of 100-300 micron width; and providing desired yield strength in the cast strip by cooling the strip to transform the austenite grains to ferrite in a temperature range between 850° C. and 400° C. at a selected cooling rate of at least 0.01° C./sec to produce a microstructure that provides a strip having a yield strength of at least 200 MPa. The low carbon steel produced desired microstructure.

Abstract: A method of controlling a continuous steel strip casting process based on customer-specified requirements includes a general purpose computer in which product specifications of steel product ordered by a customer is entered. The computer is configured to automatically map the product specifications to process parameters/set points for controlling the continuous steel strip casting process in a manner to produce the customer ordered product, and in one embodiment produces a process change report detailing such process parameters/set points for operator use in physically implementing such process parameters/set points in the strip casting process. Alternatively, the computer may provide the process parameters/set points directly to the strip casting process for automatic control thereof in producing the customer ordered steel product.

Abstract: A system for determining process parameters for the ladle refinement of steel includes a computer executing a number of software algorithms for determining one or more process parameters for various steel refinement process steps. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. In another embodiment, the computer is configured to determine the total quantity of oxygen to be injected into the steel as part of a steel reoxidation process. In still another embodiment, the computer is configured to determine a melting temperature of inclusions within the refined steel, and to determine whether this melting temperature is within an acceptable range to successfully process the steel in a continuous steel strip casting apparatus/process, or whether the steel must be reworked to achieve an acceptable inclusion melting temperature.

Abstract: A model-based strategy is provided for determining casting roll operating temperature in a continuous thin strip casting process. A first temperature sensor produces a first temperature signal indicative of the temperature of cooling liquid supplied to the casting rolls and a second temperature sensor produces a second temperature signal indicative of the temperature of cooling liquid temperature exiting the casting rolls. A computer determines a heat flux value as a function of the first and second temperature signals, and computes the operating temperature of the casting rolls as a function of the heat flux value, the second temperature signal and a number of constants defined by fixed-valued operating parameters of the continuous thin strip casting process. A control strategy is also provided to modify one or more operating parameters of the continuous thin strip casting process as a function of the casting roll temperature.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip of no more than 5 mm thickness having austenite grains that are coarse grains of 100-300 micron width; and providing desired yield strength in the cast strip by cooling the strip to transform the austenite grains to ferrite in a temperature range between 850° C. and 400° C. at a selected cooling rate of at least 0.01° C./sec to produce a microstructure that provides a strip having a yield strength of at least 200 MPa. The low carbon steel produced desired microstructure.

Abstract: A model-based strategy is provided for determining casting roll operating temperature in a continuous thin strip casting process. A first temperature sensor produces a first temperature signal indicative of the temperature of cooling liquid supplied to the casting rolls and a second temperature sensor produces a second temperature signal indicative of the temperature of cooling liquid temperature exiting the casting rolls. A computer determines a heat flux value as a function of the first and second temperature signals, and computes the operating temperature of the casting rolls as a function of the heat flux value, the second temperature signal and a number of constants defined by fixed-valued operating parameters of the continuous thin strip casting process. A control strategy is also provided to modify one or more operating parameters of the continuous thin strip casting process as a function of the casting roll temperature.

Abstract: A method of controlling a continuous steel strip casting process based on customer-specified requirements includes a general purpose computer in which product specifications of steel product ordered by a customer is entered. The computer is configured to automatically map the product specifications to process parameters/set points for controlling the continuous steel strip casting process in a manner to produce the customer ordered product, and in one embodiment produces a process change report detailing such process parameters/set points for operator use in physically implementing such process parameters/set points in the strip casting process. Alternatively, the computer may provide the process parameters/set points directly to the strip casting process for automatic control thereof in producing the customer ordered steel product.

Abstract: A method of controlling a continuous steel strip casting process based on customer-specified requirements includes a general purpose computer in which product specifications of steel product ordered by a customer is entered. The computer is configured to automatically map the product specifications to process parameters/set points for controlling the continuous steel strip casting process in a manner to produce the customer ordered product, and in one embodiment produces a process change report detailing such process parameters/set points for operator use in physically implementing such process parameters/set points in the strip casting process. Alternatively, the computer may provide the process parameters/set points directly to the strip casting process for automatic control thereof in producing the customer ordered steel product.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip and hot rolling the cast strip within a temperature range such that the strip passes through the Ar3 transformation temperature from austenite to ferrite under strain during rolling, thereby producing a strip having a yield strength above 400 Mpa and an elongation in excess of 30%. The cast steel strip has desired microstructures.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method for producing steel strips includes continuously casting molten steel into a strip, said molten steel comprising a concentration of residuals of 2.0 wt % or less is selected with regard to the microstructure of the finished strip to provide a desired yield strength; and cooling the strip to transform the strip from austenite to ferrite in the temperature range of 850° C. to 400° C. Cast steel with improved yield strength properties is produced by such method.

Abstract: A plain carbon steel strip is continuously cast in a twin roll caster and passes to a run out table on which it is subjected to accelerated cooling by means of cooling headers whereby it is cooled to transform the strip from austenite to ferrite at a temperature range between 850° C. and 400° C. at a cooling rate of not less than 90° C./sec, such that the strip has a yield strength of greater than 450 MPa. The strip after casting and before cooling is passed through a hot rolling mill to reduce the thickness of strip by at least 15% and up to 50%.

Abstract: Steel strips and methods for producing steel strips are provided. In an illustrated embodiment, a method includes continuously casting molten low carbon steel into a strip of no more than 5 mm thickness having austenite grains that are coarse grains of 100-300 micron width; and providing desired yield strength in the cast strip by cooling the strip to transform the austenite grains to ferrite in a temperature range between 850° C. and 400° C. at a selected cooling rate of at least 0.01 ° C./sec to produce a microstructure that provides a strip having a yield strength of at least 200 MPa. The low carbon steel produced desired microstructure.