Abstract: A nozzle end is provided with an extension 11 which has a lower portion immersed in a molten metal pool and extends toward a side weir 2 such that a stagnation area disappears on a free liquid surface of molten metal. The extension 11 is in the form of a quadrangular pyramid lying sidelong and is converged to a point P1 extremely close to the side weir 2. According to this molten metal feed nozzle, a stagnation area on a free liquid surface of molten metal is displaced by the extension 11 contiguous with the nozzle end to suppress generation of an unwanted solidification shell. Thus, no unwanted solidification shell is pinched as foreign matter by solidification shells generated on outer peripheries of chilled rolls 1 for production of a strip and break of a strip derived from enlargement of nip between the rolls can be averted.

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 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.

Abstract: A thin steel strip with low surface roughness and low porosity produced 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 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.

Abstract: A thin cast steel strip and method of making thereof with improved resistance to microcracking, where the steel strip is produced by continuous casting and contains between about 0.003% and about 0.008% sulfur by weight and about 0.010% and about 0.065% carbon by weight. The sulfur content may be between about 0.003% and 0.006%.

Abstract: A method of controlling heat flux between the casting pool and the surfaces of the casting roll in a strip steel casting process includes controlling the concentration of nitrogen in the steel melt. The concentration of nitrogen may be controlled to achieve an operational heat transfer to the casting roll. The beat flux to the casting rolls may be controlled by maintaining the sum of partial pressures calculated from the nitrogen and hydrogen concentrations in the casting pool below 1.15 atmospheres. Decreasing the concentration of nitrogen can increase heat flux at the casting rolls.

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 casting steel strip by introducing molten plain carbon steel on casting surfaces at least one casting roll with the molten steel having a free nitrogen content below 120 ppm and a free hydrogen content below about 6.9 ppm. The free nitrogen content maybe below about 100 ppm or below about 85 ppm. The free hydrogen content maybe between 1.0 and 6.5 ppm at atmospheric pressure. Novel cast strip of plain carbon steel is produced having a strip thickness less than 5 mm or less than 2 mm by use of the method.

Abstract: A method for making a thin cast strip with reduced meniscus marks includes assembling a pair of casting rolls laterally positioned to form a nip therebetween, preparing molten steel having a carbon content in the range of 0.01 to 0.3% by weight, a manganese content between 0.1 and 0.8% by weight, a silicon content between 0.05 and 0.5% by weight, a calcium content between 0.0008 and 0.004% by weight, an aluminum content between 2 and 500 ppm by weight, having a free oxygen content below about 50 ppm at 1600 ° C., forming a casting pool of the molten steel supported on casting surfaces of the casting rolls above the nip, and counter-rotating the casting rolls cause thin strip to be casted downwardly from the nip.

Abstract: In twin roll casting of steel strip, molten steel is introduced into the nip 16B between parallel casting rolls to create casting pool supported on casting surfaces of the rolls and the rolls are rotated to deliver solidified strip downwardly from the nip. Casting surfaces are textured by a random pattern of discrete projections, which may have an average surface distribution of between 5 and 200 peaks per mm2 and an average height of at least 10 microns. In order to suppress chatter defects, the molten steel also has manganese content of at least 0.55% by weight and a silicon content in the range of 0.1 to 0.35% by weight. The strip is thus capable of moving away from the casting pool at a speed of more than 60 meters per minute without substantial high speed chattering defects.

Abstract: A method of producing strip comprising the steps of assembling a pair of casting rolls with a nip between them, introducing 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, solidifying the molten steel on the rolls to form metal shells with levels of oxide inclusions reflected by the total oxygen content of the molten steel, and forming thin steel strip through the nip between the casting rolls from the solidified shells. The molten steel may have a total oxygen content is at least 100 ppm and the free oxygen content may be between 30 and 50 ppm. A unique steel strip may be obtained using the method having ductile properties.

Abstract: A steel strip made with protective layer of less than 100 nanometers with Fe203 adjacent the base metal of the strip. The steel strip may be made by assembling two casting rolls in lateral relationship to form a nip there between through which strip can be cast, forming a casting pool supported on the casting rolls above the nip at a temperature such that the temperature of the steel is greater than about 1,300° C. at the nip between the casting rolls, counter-rotating the casting rolls such that the peripheral surfaces of the casting rolls each travel toward the nip to produce a cast strip downwardly from the nip, and passing the continuous cast strip through at least one cooling chamber that has less than 5% oxygen to cool the strip to less than 150° C. or until coiled without disrupting the surface of the strip adjacent the protective layer formed.

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 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 recrystallisation for strain levels up to at least 10.0%, for temperatures up to 750 ° 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.

Abstract: A thin steel strip with low surface roughness and low porosity produced 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 molten steel having a slag of iron, manganese, silicon and aluminum oxides is formed and passed between a pair of casting rolls to form the steel strip having MnO.SiO2.Al2O3 inclusions, the inclusions having a desired ratio of MnO/SiO2.

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 casting steel strip by introducing molten plain carbon steel on casting surfaces at least one casting roll with the molten steel having a free nitrogen content below 120 ppm and a free hydrogen content below about 6.5 ppm measured at atmospheric pressure. The free nitrogen content maybe below about 100 ppm or below about 85 ppm. The free hydrogen content maybe between 1.0 and 6.5 ppm at atmospheric pressure. Novel cast strip of plain carbon steel is produced having a strip thickness less than 5 mm or less than 2 mm by use of the method.

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.