In production of a reactive metal using a melting furnace for producing metal having a hearth, ingots can be efficiently produced by efficiently cooling the ingots extracted from the mold provided in the melting furnace. In addition, an apparatus structure in which multiple ingots can be produced with high efficiency and high quality from one hearth, is provided. A melting furnace for producing metal is provided, the furnace has a hearth for having molten metal formed by melting raw material, a mold in which the molten metal is poured, an extracting jig which is provided below the mold for extracting ingot cooled and solidified downwardly, a cooling member for cooling the ingot extracted downwardly of the mold, and an outer case for keeping the hearth, the mold, the extracting jig, and the cooling member separated from the air, wherein at least one mold and extracting jig are provided in the outer case, and the cooling member is provided between the outer case and the ingot, or between the multiple ingots.

A method for semi-continuous casting of a strand (1) of steel in a strand casting machine and a strand casting machine for such casting. The strand has little segregation of the center and porosity. Yet it is castable rapidly. The method steps are: at a casting start of the strand casting machine, pouring liquid steel into an open-ended mold (2). The mold is closed by a cold strand (6). The liquid steel forms, together with the cold strand, a completely solidified strand start (1a) and subsequently forms a semi-solidified strand (1b). Then extracting the semi-solidified strand (1b) from the open-ended mold (2). Supporting and guiding the semi-solidified strand (1b) in a strand guide (3). Cooling the semi-solidified strand (1b) by secondary cooling (4) at the casting end of the strand casting machine, ending the pouring of liquid steel into the open-ended mold (2) and forming a strand end (1c). Extracting the strand end (1c) from the open-ended mold (2). Ending the extraction such that the strand end (1c) lies outside the open-ended mold (2). Ending the secondary cooling (4). Controlling or regulating cooling of the semi-solidified strand (1b) until complete solidification of the strand (1) in a tertiary cooling zone (5) of the strand casting machine. The cooling effect is stronger at the strand start (1a) and decreases towards the strand end (1c). Discharging the strand (1) from the strand casting machine.

A method for semi-continuous casting of a strand (1) of steel in a strand casting machine and a strand casting machine for such casting. The strand has little segregation of the center and porosity. Yet it is castable rapidly. The method steps are: at a casting start of the strand casting machine, pouring liquid steel into an open-ended mold (2). The mold is closed by a cold strand (6). The liquid steel forms, together with the cold strand, a completely solidified strand start (1a) and subsequently forms a semi-solidified strand (1b). Then extracting the semi-solidified strand (1b) from the open-ended mold (2). Supporting and guiding the semi-solidified strand (1b) in a strand guide (3). Cooling the semi-solidified strand (1b) by secondary cooling (4) at the casting end of the strand casting machine, ending the pouring of liquid steel into the open-ended mold (2) and forming a strand end (1c). Extracting the strand end (1c) from the open-ended mold (2). Ending the extraction such that the strand end (1c) lies outside the open-ended mold (2). Ending the secondary cooling (4). Controlling or regulating cooling of the semi-solidified strand (1b) until complete solidification of the strand (1) in a tertiary cooling zone (5) of the strand casting machine. The cooling effect is stronger at the strand start (1a) and decreases towards the strand end (1c). Discharging the strand (1) from the strand casting machine.

Crystallizer for the continuous high-speed casting of a metal product (P), which has a casting cavity (13) defined by walls (14) connected to each other in correspondence with edges (15) and provided with cooling means (16).

Crystallizer for the continuous high-speed casting of a metal product (P), which has a casting cavity (13) defined by walls (14) connected to each other in correspondence with edges (15) and provided with cooling means (16).

A method for improving center segregation and surface crack of continuous casting medium-thick slab of peritectic steel reduces the cooling intensity at the earlier stage of solidification and enhancing the cooling intensity at the final stage of solidification. For example, the cooling water amount of the wide face of the mould is 3400-3600 L/min, and the cooling water amount of the narrow face of the mould is 480-530 L/min. The cooling water amount of the wide face of the foot roller section is 239-298 L/min, and the cooling water amount of the narrow face of the foot roller section is 61-65 L/min. The total cooling water amount of the sector segment is 1517-2166 L/min.

A method for casting longitudinal cast products including casting longitudinal cast products in a semi-continuous manner using a DC casting apparatus having a mold, wherein the mold has top and bottom openings and partially solidifies molten metal that enters into the mold via the top opening and outputs the cast product via the bottom opening, recording a thermal image of the cast product output via the bottom opening, determining at least three non-overlapping temperature ranges comprising a first, second and third, determining a peak temperature in the thermal image; comparing the peak temperature with the at least three temperature ranges; and performing operations depending on where the peak temperature falls within the at least three temperature ranges.

A method for casting longitudinal cast products including casting longitudinal cast products in a semi-continuous manner using a DC casting apparatus having a mold, wherein the mold has top and bottom openings and partially solidifies molten metal that enters into the mold via the top opening and outputs the cast product via the bottom opening, recording a thermal image of the cast product output via the bottom opening, determining at least three non-overlapping temperature ranges comprising a first, second and third, determining a peak temperature in the thermal image; comparing the peak temperature with the at least three temperature ranges; and performing operations depending on where the peak temperature falls within the at least three temperature ranges.

Continuous casting mold is provided having a mold copper plate having plural separate portions filled with foreign metal formed by filling concave grooves formed on the inner wall surface of the mold copper plate and having a diameter of 2 mm to 20 mm in the inner wall surface at least in the region from a meniscus to a position located 20 mm or more lower than the meniscus with the foreign metal whose thermal conductivity is 80% or less or 125% or more of the mold copper plate, the ratio of the Vickers hardness HVc of the mold copper plate to the Vickers hardness HVm of the filling metal satisfies expression (1), and the ratio of the thermal expansion coefficient αc of the mold copper plate and the thermal expansion coefficient αm of the filling metal satisfies expression (2).
0.3≤HVc/HVm≤2.3  (1),
0.7≤αc/αm≤3.5  (2)

Continuous casting mold is provided having a mold copper plate having plural separate portions filled with foreign metal formed by filling concave grooves formed on the inner wall surface of the mold copper plate and having a diameter of 2 mm to 20 mm in the inner wall surface at least in the region from a meniscus to a position located 20 mm or more lower than the meniscus with the foreign metal whose thermal conductivity is 80% or less or 125% or more of the mold copper plate, the ratio of the Vickers hardness HVc of the mold copper plate to the Vickers hardness HVm of the filling metal satisfies expression (1), and the ratio of the thermal expansion coefficient αc of the mold copper plate and the thermal expansion coefficient αm of the filling metal satisfies expression (2).
0.3≤HVc/HVm≤2.3  (1),
0.7≤αc/αm≤3.5  (2)