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.

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.

A cold rolling facility includes: a heating device; a tandem mill including a plurality of rolling mills; a meandering-amount measuring unit; a meandering-movement correction device; a shape measuring unit; a shape controller configured to control a shape of a steel sheet after being cold-rolled by the rolling mill located on the uppermost stream side; and a controller configured to control operations of the meandering-movement correction device based on a measurement value of a meandering-movement amount of the steel sheet by the meandering-amount measuring unit to control a meandering movement of the steel sheet before being heated, and configured to control operations of the shape controller based on a measurement value of a shape of the steel sheet by the shape measuring unit to control the meandering movement of the steel sheet that is attributed to cold rolling of the steel sheet by the tandem mill.

Manufacturing a cold-rolled steel plate, having a steel slab having the chemical composition containing, on the basis of percent by mass, C from 0.03 to 0.08%, Si from 0 to 1.0%, Mn from 0.2 to 0.8%, P at 0.03% or less, S at 0.01% or less, and Al at 0.05% or less so as to satisfy the following: formula (1) and at least one of Nb from 0.03 to 0.4%, V from 0.01 to 0.3%, and Ti from 0.01 to 0.3% so as to satisfy the following formula (2), with a residue being formed of Fe and unavoidable impurities. The steel slab is heated to 1200 C. or more and hot rolled to form a hot-rolled steel plate, which is wound from 550 to 700 C. to form a hot-rolled coil, and the hot-rolled coil is cold rolled or annealed and cold rolled, obtaining cross-sectional hardness from 200 to 350 HV.

A plant and process for the continuous production of hot-rolled steel strips with a minimum thickness of 0.3 mm is disclosed which includes a continuous casting device of thin or medium slabs with a thickness between 40 and 150 mm and a maximum width of at least 2100 mm followed by a roughing mill, a first induction furnace, a water descaler, a second induction furnace, a finishing mill, a cooling station, a cutting station and a winding station. A system for feeding a protective atmosphere containing ?3% vol. oxygen is provided from the inlet of the second induction furnace to at least the third stand of the finishing mill. Between the continuous casting device and the roughing mill, an initial thermal conditioning and descaling section is provided having in sequence an induction edge heater, an induction heater for the rest of the slab surface and a water descaler.

A rolling plant and method for producing a strip starting from a slab having a certain starting thickness, comprising at least one walking beam heating furnace configured to heat at least the slab to a starting temperature, and a rolling train operatively disposed in line with at least one roughing stand and configured to reduce the thickness of an intermediate rolled product at exit from the roughing stand, until the final strip is obtained; the rolling train comprising at least one pre-finishing stand for obtaining a pre-finished rolled product, and a plurality of finishing stands for obtaining the final strip; the plant comprising load cells directly associated with the pre-finishing stand for detecting the rolling force applied on the pre-finished rolled product, a rapid heating device, interposed between the pre-finishing stand and the finishing stands, for heating the pre-finished rolled product, and a command and control unit connected both to the load cells and also to the rapid heating device and configured at least to selectively activate the latter, at least as a function of the rolling force detected by the load cells.

A cold-rolled steel plate having favorable heat spot resistance and favorable antiwear performance is provided. The cold-rolled steel plate has a chemical composition containing C from 0.03 to 0.12%, Si from 0 to 1.0% (including a case where Si is not added), Mn from 0.2 to 0.8%, P at 0.03% or less (excluding a case where P is not added), S at 0.03% or less (excluding a case where S is not added), Ti from 0.04 to 0.3%, and Al at 0.05% or less (excluding a case where Al is not added). A residue is formed of Fe and unavoidable impurities. Each element satisfies a relationship of 5*C %Si %+Mn %1.5*Al %<1 within the aforementioned range of the corresponding content. An average diameter of particles of a Ti-based carbide is from 20 to 100 nm. In this way, the Ti-based carbide is dispersed finely and uniformly, thereby enhancing heat spot resistance and antiwear performance.

A cold rolling apparatus includes: a heating device configured to heat a sequentially transferred steel sheet; a cold rolling mill configured to sequentially cold-roll the steel sheet after being heated; a meandering-movement correction device arranged on an upstream side of the heating device in a transfer direction of the steel sheet, and configured to correct a meandering movement of the steel sheet transferred toward the heating device; and a meandering-movement suppression device arranged between the heating device and the cold rolling mill, and configured to suppress a meandering movement of the steel sheet attributed to the cold rolling of the steel sheet by using the cold rolling mill.

A production equipment line for a hot-rolled steel strip comprises a rough rolling mill comprising rough rolling mills for hot rolling a material, which is heated to a predetermined temperature to a finish rolling start sheet thickness and a finish rolling mill comprising finish rolling mills for controlled-rolling the material to a final sheet thickness. At least one of the rough rolling mills is a reversible rolling mill. The production equipment line is provided on an upstream side of the reversible rolling mill with one of a slow cooling apparatus for slowly cooling at a water volume density of less than 1000 L/min.Math.m.sup.2 and a rapid cooling apparatus for rapidly cooling after the slow-cooling at a water volume density of not less than 1000 L/min.Math.m.sup.2 and the other of the slow cooling apparatus and rapid cooling apparatus on a downstream side of the reversible rolling mill.

A rolling process for long solid-section products includes the steps of rolling stock through a plurality of rolling mill stands, the rolled stock being subjected to a tensile load, between the plurality of stands, that generates a single-axial deformation greater than 0.1 in the rolling direction, and is also deformed by compression between the rolls of at least one of the rolling mill stands, thereby achieving a reduction in the cross section area of at least 5%, preferably of between 5 and 50%. A rolling mill, in which a plurality of stands is connected by spacer elements designed to offset the tensile load; a rolling mill, in which a plurality of stands is connected by elements designed to offset the overturning moment generated by the tensile load; and a rolling mill, in which the aforesaid rolling stands maintain a non-slip condition.