Abstract: Provided is an ultra high-strength hot-rolled steel sheet, having tensile strength of 800 MPa, and a method for manufacture same, the method enabling excellent surface quality, workability, weldability as well as significantly reduced deviation of the mechanical property in the width and length directions of the steel sheet by means of an endless rolling mode in a continuous casting-direct rolling process.

Abstract: A continuous casting and rolling apparatus includes: a continuous casting device; a cutting device that is disposed at the output side of the continuous casting device and cuts an inner slab produced from the continuous casting device; a rolling device pressing down on the slab and disposed downstream of the continuous casting device in the moving direction of the inner slab; a tunnel furnace which is disposed between the cutting device and the rolling device and heats the slab disposed on the main path of the inner slab that is transferred from the continuous casting device to the rolling device; and a loading adjustment unit which is disposed adjacent to the tunnel furnace and unloads the slab from the main path from the outlet side of the tunnel furnace and loads the slab onto the main path from the inlet side of the tunnel furnace.

Abstract: Provided is an ultra high-strength hot-rolled steel sheet, having tensile strength of 800 MPa, and a method for manufacture same, the method enabling excellent surface quality, workability, weldability as well as significantly reduced deviation of the mechanical property in the width and length directions of the steel sheet by means of an endless rolling mode in a continuous casting-direct rolling process.

Abstract: A continuous casting and rolling apparatus according to one embodiment of the present invention provides: a continuous caster for generating a steel sheet; a first rolling unit associated with the continuous caster; and a second rolling unit which is spaced apart in the outlet of the first rolling unit and comprises: a rolling mill for pressing down the steel sheet; and a cutter for cutting a portion of the steel sheet, wherein the cutter is spaced from the second rolling unit by a length corresponding to the length of the steel sheet discharged in an at least discontinuous rolling mode, and may comprise a cut withdrawal unit provided between the first rolling unit and the second rolling unit.

Abstract: A continuous casting and rolling apparatus according to one embodiment of the present invention comprises: a continuous casting apparatus for producing a steel sheet; a roller, linked to the continuous casting apparatus, for receiving the steel sheet; and a push heat unit, connected to the continuous casting apparatus and/or the roller, for selectively carrying outing heating work or removal work with respect to a portion of the steel sheet. Also, a continuous casting and rolling method according to another embodiment of the present invention may comprise: a continuous casting step for producing a steel sheet; and a selective performance step for selectively carrying out heating work or removal work with respect to a portion of the steel sheet.

Abstract: A hot rolling device, according to one embodiment of the present invention, may comprise: a cast part supply portion for producing a cast part; a hot roller, linked to the cast part supply portion, for receiving and hot-rolling the cast part; and a heating unit, arranged between the cast part supply portion and the hot roller, for reheating an outer surface portion in the widthwise direction of the cast part while latent heat is maintained in the center portion of the widthwise direction of the cast part from preheating.

Abstract: Provided is an endless rolling apparatus and method, which have improved cooling conditions for producing advanced high strength steel. The endless rolling apparatus includes: a continuous casting machine for casting a slab; and a cooling bed having at least one piece of water-cooling equipment and at least one rolling mill continuously connected to the continuous casting machine, wherein, in the cooling bed, an initial position (S) at which the water-cooling equipment is provided so as to manufacture advanced high strength steel through at least one water-cooling is defined by mathematical formula 1. Here, H is the thickness (mm) of a slab, V is the casting speed (m/sec) of the slab, h is the product thickness (mm), and t is the target arrival time (sec) until entry into the cooling bed.

Abstract: Provided is a continuous casting and rolling method, which includes: a continuous casting operation of producing a slab; and a rolling operation of pressing the slab after a front end portion of the slab passes a first rolling stand into which the front end portion of the slab, which is provided as a continuous body to the slab produced in the continuous casting operation, initially enters.

Abstract: A continuous casting and rolling apparatus according to one embodiment of the present invention comprises: a continuous casting apparatus for producing a steel sheet; a roller, linked to the continuous casting apparatus, for receiving the steel sheet; and a push heat unit, connected to the continuous casting apparatus and/or the roller, for selectively carrying outing heating work or removal work with respect to a portion of the steel sheet. Also, a continuous casting and rolling method according to another embodiment of the present invention may comprise: a continuous casting step for producing a steel sheet; and a selective performance step for selectively carrying out heating work or removal work with respect to a portion of the steel sheet.

Abstract: A hot rolling device, according to one embodiment of the present invention, may comprise: a cast part supply portion for producing a cast part; a hot roller, linked to the cast part supply portion, for receiving and hot-rolling the cast part; and a heating unit, arranged between the cast part supply portion and the hot roller, for reheating an outer surface portion in the widthwise direction of the cast part while latent heat is maintained in the center portion of the widthwise direction of the cast part from preheating.

Abstract: A continuous casting and rolling apparatus according to one embodiment of the present invention provides: a continuous caster for generating a steel sheet; a first rolling unit associated with the continuous caster; and a second rolling unit which is spaced apart in the outlet of the first rolling unit and comprises: a rolling mill for pressing down the steel sheet; and a cutter for cutting a portion of the steel sheet, wherein the cutter is spaced from the second rolling unit by a length corresponding to the length of the steel sheet discharged in an at least discontinuous rolling mode, and may comprise a cut withdrawal unit provided between the first rolling unit and the second rolling unit.