A ladle bottom being part of a metallurgical ladle for treating a metal melt as well as a corresponding metallurgical ladle.

A ladle bottom being part of a metallurgical ladle for treating a metal melt as well as a corresponding metallurgical ladle.

A ladle bottom being part of a metallurgical ladle for treating a metal melt as well as a corresponding metallurgical ladle.

A tundish, wherein a steel passing hole (43) is provided at a lower portion of a gas-curtain weir refractory body (42); an argon duct (46), a gas chamber (45) and a gas-permeable brick (44) are connected to form a gas-curtain generating device, and the gas-curtain generating device is installed at the lower portion of the gas-curtain weir refractory body (42); the gas-permeable brick (44) is provided in association with the position of the steel passing hole (43), and a length of the gas-permeable brick is designed larger than a width of the steel passing hole (43); and a gas-curtain weir plate (4) is provided in a tundish container, the gas-curtain weir refractory body (42) crosses the tundish container horizontally, and divides the tundish container into a first region and a second region.

A tundish, wherein a steel passing hole (43) is provided at a lower portion of a gas-curtain weir refractory body (42); an argon duct (46), a gas chamber (45) and a gas-permeable brick (44) are connected to form a gas-curtain generating device, and the gas-curtain generating device is installed at the lower portion of the gas-curtain weir refractory body (42); the gas-permeable brick (44) is provided in association with the position of the steel passing hole (43), and a length of the gas-permeable brick is designed larger than a width of the steel passing hole (43); and a gas-curtain weir plate (4) is provided in a tundish container, the gas-curtain weir refractory body (42) crosses the tundish container horizontally, and divides the tundish container into a first region and a second region.

Casting of iron or steel is performed by assembling a charge (1) of plate-like charge elements (1a, 1b, 1c . . . ) with known compositions and dimensions by placing them on top of each other, and of an alloying component entity (2) with known composition, such as alloying component pieces or an alloying component cartridge, by means of which the composition of the charge is balanced to the desired precise composition. The charge is melted in a furnace (5) and cast to form a casting with an exactly known composition.

Casting of iron or steel is performed by assembling a charge (1) of plate-like charge elements (1a, 1b, 1c . . . ) with known compositions and dimensions by placing them on top of each other, and of an alloying component entity (2) with known composition, such as alloying component pieces or an alloying component cartridge, by means of which the composition of the charge is balanced to the desired precise composition. The charge is melted in a furnace (5) and cast to form a casting with an exactly known composition.

A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2 exists entirety or partially in a surface of each of the MgO-containing particles.

With a view to adding, to an upper nozzle formed with a bore having a shape capable of creating a less energy loss or smooth (constant) molten steel flow to suppress the occurrence of adhesion of inclusions and metals in molten steel, a gas injection function to thereby further suppress the occurrence of the adhesion, the present invention provides a method of using an upper nozzle configured to have a cross-sectional shape of a wall surface defining the bore, taken along an axis of the bore, comprising a curve represented by the following formula: log(r (z))=(1/n)×log((H+L)/(H+z))+log(r (L)) (n=1.5 to 6), where: L is a length of the upper nozzle; H is a calculational hydrostatic head height; and r (z) is an inner radius of the bore at a position downwardly away from an upper edge of the bore by a distance z. The method comprises using the upper nozzle in such a manner as to satisfy the following relationship: R.sub.G≦4.3×V.sub.L, where R.sub.G is a gas rate defined as a volume ratio of a flow rate Q.sub.G (Nl/s) of injection gas to a flow rate Q.sub.L (l/s) of molten steel flowing through the bore (R.sub.G=(Q.sub.G/Q.sub.L)×100(%)), and V.sub.L is a flow speed of the molten steel at a lower edge of the upper nozzle.

With a view to adding, to an upper nozzle formed with a bore having a shape capable of creating a less energy loss or smooth (constant) molten steel flow to suppress the occurrence of adhesion of inclusions and metals in molten steel, a gas injection function to thereby further suppress the occurrence of the adhesion, the present invention provides a method of using an upper nozzle configured to have a cross-sectional shape of a wall surface defining the bore, taken along an axis of the bore, comprising a curve represented by the following formula: log(r (z))=(1/n)×log((H+L)/(H+z))+log(r (L)) (n=1.5 to 6), where: L is a length of the upper nozzle; H is a calculational hydrostatic head height; and r (z) is an inner radius of the bore at a position downwardly away from an upper edge of the bore by a distance z. The method comprises using the upper nozzle in such a manner as to satisfy the following relationship: R.sub.G≦4.3×V.sub.L, where R.sub.G is a gas rate defined as a volume ratio of a flow rate Q.sub.G (Nl/s) of injection gas to a flow rate Q.sub.L (l/s) of molten steel flowing through the bore (R.sub.G=(Q.sub.G/Q.sub.L)×100(%)), and V.sub.L is a flow speed of the molten steel at a lower edge of the upper nozzle.