A device for achieving a core part press-down technology in a continuous casting round billet solidification process includes a plurality of round billet radial press-down devices distributed along an axial array of round billets outside a press-down interval of the round billets. The press-down interval is an area from 0.65 of a solid phase ratio of the round billets to solidification end points. Each round billet radial press-down device includes a plurality of press-down rollers. A forming hole for extruding the round billets is formed between the press-down rollers. Two adjacent round billet radial press-down devices are arranged in the manner of staggering. The device can effectively solve the defect problems of porosity, segregation and the like in the core of the continuous casting round billets, the yield of the continuous casting round billets is increased, and the production cost is reduced.

In the continuous steel casting method of the present invention, a gap between strand support rolls with a strand in a rectangular shape interposed therebetween is increased toward a downstream side in a casting direction to thereby bulge the strand having an unsolidified layer thereinside such that the thickness between long-side surfaces of the strand increases within the range of 0.1% or more and 10% or less of the thickness of the strand inside a mold. A portion of the strand in which the solid phase fraction in a central portion of the strand is within the range of 0.2 or more and less than 0.9 satisfies a prescribed total rolling reduction and a prescribed reduction gradient, and a portion of the strand in which the solid phase fraction is within the range of 0.9 or more satisfies a prescribed total rolling reduction and a prescribed reduction gradient.

A crack-free continuous casting mold configured so that occurrence of cracks at a casting billet can be reduced even in a case where a casting speed exceeds 500 mm/min. The continuous casting mold continuously casts a casting billet while cooling molten metal by a cooling device provided at a cooling casting mold. The cooling device includes multiple cooling nozzles configured to release coolant water to the casting billet pulled out of the cooling casting mold to cool the casting billet. Multiple ejection ports of the multiple cooling nozzles are arranged along an outer circumferential direction of a surface of the casting billet. Each ejection port has a short side and a long side, and is configured such that the long side is arranged along an axial direction of the casting billet.

A continuous casting method of steel includes the step of bulging wide side surfaces of a slab having there inside an unsolidified layer with a total intentional bulging amount of 3 to 10 mm by increasing stepwise toward a downstream side in a casting direction a roller gap of a plurality of pairs of slab support rollers disposed in a continuous casting machine.

A continuous steel casting method includes producing a strand. The producing of the strand includes pouring molten steel into a mold of a continuous casting machine and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel. The method includes applying a static magnetic field to at least a portion of a region of the strand, the strand being in the continuous casting machine, the region being a region where a solid fraction fs at a thickness-wise middle position of the strand is in a given range, the static magnetic field having a magnetic field strength of greater than or equal to 0.15 T and being in a direction orthogonal to a direction in which the strand is withdrawn, the static magnetic field being applied at an application time ratio of greater than or equal to 10%.

A system for on-line measuring the thickness of a continuous casting billet and adjusting a rolling reduction amount, is capable of giving an accurate, constant and rapid feedback on the thickness of the billet in the continuous casting process online, avoiding the deviation of the rolling reduction amount of the billet in the continuous casting production process which is triggered by the factors such as the capacity of the continuous casting equipment, the execution deviation of the rolling reduction process, the metal solidification attribute such as non-preset expansion and contraction, so as to maximize the function of the continuous casting rolling reduction and improve the solidification quality of the billet.

A monitoring and control system is for a strand guide roll assembly of a continuous casting machine which includes a plurality of rolls spaced apart generally along a path of travel of a strand from an input end located adjacent to a mold to an output end. The system includes a plurality of sensors each coupled with a separate one of the rolls so as to be spaced apart generally along the travel path, each sensor senses magnitude of a load on the coupled roll. A logic circuit is coupled with each sensor so as to receive input from the sensors corresponding to load magnitude. The logic circuit is configured to determine from the sensor input a general position on the travel path at which the strand substantially solidifies, preferably by calculating a difference between loads on adjacent rolls and determining when the difference is less than a predetermined value.

In the continuous steel casting method of the present invention, a gap between strand support rolls with a strand in a rectangular shape interposed therebetween is increased toward a downstream side in a casting direction to thereby bulge the strand having an unsolidified layer thereinside such that the thickness between long-side surfaces of the strand increases within the range of 0.1% or more and 10% or less of the thickness of the strand inside a mold. A portion of the strand in which the solid phase fraction in a central portion of the strand is within the range of 0.2 or more and less than 0.9 satisfies a prescribed total rolling reduction and a prescribed reduction gradient, and a portion of the strand in which the solid phase fraction is within the range of 0.9 or more satisfies a prescribed total rolling reduction and a prescribed reduction gradient.

The present invention discloses a device and method for achieving a core part press-down technology in a continuous casting round billet solidification process. The device includes a plurality of round billet radial press-down devices distributed along an axial array of round billets outside a press-down interval of the round billets. The press-down interval is an area from 0.65 of a solid phase ratio of the round billets to solidification end points. Each round billet radial press-down device comprises a plurality of press-down rollers. A forming hole for extruding the round billets is formed between the press-down rollers. Two adjacent round billet radial press-down devices are arranged in the manner of staggering. The device can effectively solve the defect problems of porosity, segregation and the like in the core of the continuous casting round billets, the yield of the continuous casting round billets is increased, and the production cost is reduced.

A crack-free continuous casting mold configured so that occurrence of cracks at a casting billet can be reduced even in a case where a casting speed exceeds 500 mm/min. The continuous casting mold continuously casts a casting billet while cooling molten metal by a cooling device provided at a cooling casting mold. The cooling device includes multiple cooling nozzles configured to release coolant water to the casting billet pulled out of the cooling casting mold to cool the casting billet. Multiple ejection ports of the multiple cooling nozzles are arranged along an outer circumferential direction of a surface of the casting billet. Each ejection port has a short side and a long side, and is configured such that the long side is arranged along an axial direction of the casting billet.