Abstract: This slab is a slab of high-Al steel containing C: 0.02 mass% to 0.50 mass% and Al: 0.20 mass% to 2.00 mass%, in which, in a case where [Zr], [Al], and [N] each represent a content (mass%) in the slab, a Zr content satisfies a relationship of [Zr] ? 4/3 × [Al] × [N].

Abstract: This slab is a slab of high-Al steel containing C: 0.02 mass % to 0.50 mass % and Al: 0.20 mass % to 2.00 mass %, in which, in a case where [Zr], [Ti], [Al], and [N] each represent a content (mass %) in the slab, a Zr content and a Ti content satisfy a relationship of [Zr]+0.2×[Ti]?4/3×[Al]×[N], and the Zr content satisfies a relationship of 0.0010 mass %?[Zr].

Abstract: In a first cooling zone (21) on an upper side of a vertical section (20), an air-water ratio A1/R1 defined by an amount of water R1 (L/min) and an amount of air A1 (L/min) per one cooling spray nozzle is set to 10 or more, an impinging pressure of cooling water colliding with the surface of a slab (1) from the cooling spray nozzle is set to 12 gf/cm2 or more, a cooling intensity W1×t1 defined by a cooling water density (W1) (L/min/m2) and a passing time t1 (min) of the first cooling zone (21) is 350 or more, and a recuperating time from having passed through the first cooling zone (21) until reaching a bent section (30) is set to 0.5 min or more.

Abstract: In a first cooling zone (21) on an upper side of a vertical section (20), an air-water ratio A1/R1 defined by an amount of water R1 (L/min) and an amount of air A1 (L/min) per one cooling spray nozzle is set to 10 or more, an impinging pressure of cooling water colliding with the surface of a slab (1) from the cooling spray nozzle is set to 12 gf/cm2 or more, a cooling intensity W1×t1 defined by a cooling water density (W1) (L/min/m2) and a passing time t1 (min) of the first cooling zone (21) is 350 or more, and a recuperating time from having passed through the first cooling zone (21) until reaching a bent section (30) is set to 0.5 min or more.

Abstract: To provide a continuous casting method according to which a slab difficult for surface cracking to appear can be manufactured, in a first water cooling step, the slab is cooled so that only a surface temperature of corner parts is below Ar3 point, in a first recuperation step, the slab is recuperated so that the surface temperature of all the slab including the corner parts is no less than the Ar3 point, in a second water cooing step, the slab is cooled so that the surface temperature of all the slab including the corner parts is below the Ar3 point, and in a second recuperation step, the slab is recuperated so that the surface temperature of only a portion of the slab other than the corner parts is no less than the Ar3 point.

Abstract: To provide a continuous casting method according to which a slab difficult for surface cracking to appear can be manufactured, in a first water cooling step, the slab is cooled so that only a surface temperature of corner parts is below Ar3 point, in a first recuperation step, the slab is recuperated so that the surface temperature of all the slab including the corner parts is no less than the Ar3 point, in a second water cooing step, the slab is cooled so that the surface temperature of all the slab including the corner parts is below the Ar3 point, and in a second recuperation step, the slab is recuperated so that the surface temperature of only a portion of the slab other than the corner parts is no less than the Ar3 point.