A method for producing a steel strip containing, in addition to iron as the main component and unavoidable impurities, one or more of the following oxygen-affine elements in wt. %: Al: more than 0.02, Cr: more than 0.1, Mn: more than 1.3 or Si: more than 0.1, where the surface of the steel strip is cleaned, oxidation-treated and annealed. The treated and annealed steel strip is subsequently coated with a hot-dip coat. In order to be less cost-intensive and to achieve uniform, reproducible adhesion conditions for the coat, the steel strip is oxidation-treated prior to the annealing at temperatures below 200° C., where on the surface of the steel strip, with the formation of oxides with iron from the steel strip, an oxide layer is formed, which contains iron oxide and is reduction-treated during the course of the annealing under a reducing atmosphere to achieve a surface consisting substantially of metallic iron.

The present cooling device includes: when cooling regions obtained by dividing an entire cooling region into a plurality of portions in a steel sheet conveyance direction and three or more portions in a width direction are set as divided cooling surfaces, a cooling water nozzle 23 and a switching device that switches between collision and non-collision of cooling water jetted from the cooling water nozzle 23 with the divided cooling surface, the cooling water nozzle 23 and the switching device provided for each of the divided cooling surfaces; and a control device that controls operation of the switching device based on a width-direction temperature distribution. The cooling water nozzle 23 has a jet axis P inclined with respect to a vertical line to the entire cooling region when viewed in the steel sheet conveyance direction, and the cooling water goes to the side opposite to the cooling water nozzle 23 in the width direction after colliding with the divided cooling surface.

The invention relates to a temperature-control device for partially cooling a component, wherein the component is blown on with a fluid in the region to be cooled by means of a nozzle. The nozzle comprises a connecting tube which is connected to a fluid reservoir in a fluid-conducting manner and which is connected to a plurality of nozzle tubes in a fluid-conducting manner.

The invention relates to a temperature-control device for partially cooling a component, wherein the component is blown on with a fluid in the region to be cooled by means of a nozzle. The nozzle comprises a connecting tube which is connected to a fluid reservoir in a fluid-conducting manner and which is connected to a plurality of nozzle tubes in a fluid-conducting manner.

The invention relates to a method and a device for rapidly cooling a metal strip and removing residues present on the strip after this cooling, wherein the residues are formed during a cooling of said metal strip by a non-oxidizing liquid solution for the metal strip and a stripping liquid solution for the oxides present on the surface of the strip, or by a mixture of this liquid solution and a gas.

The invention relates to a method and a device for rapidly cooling a metal strip and removing residues present on the strip after this cooling, wherein the residues are formed during a cooling of said metal strip by a non-oxidizing liquid solution for the metal strip and a stripping liquid solution for the oxides present on the surface of the strip, or by a mixture of this liquid solution and a gas.

A direct flame furnace burner unit for furnaces for the thermo-chemical treatment of steel strips in continuous hot-dip galvanizing plants includes a burner with a combustion head provided with a combustion chamber having an outlet opening of the combustion flame, and a body to which the combustion head is fixed. The body includes a first chamber which is in communication with the combustion chamber, a first lance for the injection of a fuel into the combustion chamber, a mixing chamber provided with at least a first inlet and a second inlet opening which is connectable to a second supply source, at least a second lance for the injection of the mixture into the combustion chamber. The burner is operable in two distinct operating modes, a diffusive flame combustion mode and a premixed flame combustion mode.

A direct flame furnace burner unit for furnaces for the thermo-chemical treatment of steel strips in continuous hot-dip galvanizing plants includes a burner with a combustion head provided with a combustion chamber having an outlet opening of the combustion flame, and a body to which the combustion head is fixed. The body includes a first chamber which is in communication with the combustion chamber, a first lance for the injection of a fuel into the combustion chamber, a mixing chamber provided with at least a first inlet and a second inlet opening which is connectable to a second supply source, at least a second lance for the injection of the mixture into the combustion chamber. The burner is operable in two distinct operating modes, a diffusive flame combustion mode and a premixed flame combustion mode.

A cooling roll including an axle and a sleeve, the sleeve having a length and a diameter and being structured as follows: an inner cylinder, a plurality of magnets disposed along at least a portion of the inner cylinder length, each magnet being defined by a width, a height and a length, a cooling system surrounding at least a portion of the plurality of magnets, the cooling system and the plurality of magnets being separated by a gap defined by a height, the gap height being the smallest distance between a magnet and the cooling system above, the magnets having a width such that the following formula is satisfied:
gap height×1.1≤magnet width≤gap height×8.6.

The steel sheet of the present invention has a steel microstructure containing, in area fraction, martensite: from 20% to 100%, ferrite: from 0% to 80%, and another metal phase: 5% or less, and in which a ratio of a dislocation density in metal phases on a surface of the steel sheet to a dislocation density in the metal phases in a thicknesswise central portion of the steel sheet is from 30% to 80%. The maximum amount of warpage of the steel sheet when the steel sheet is sheared to a length of 1 m in a rolling direction is 15 mm or less.