Provided is an apparatus for cooling a hot-dip plated steel sheet, the apparatus being capable of reducing comb-pattern surface defects occurring on the edge portion of the hot-dip plated steel sheet. The apparatus includes: a gas knife for spraying wiping gas to a steel sheet that has passed through a plating bath, thereby adjusting the plating thickness thereof; a defect prevention portion installed downstream of the gas knife so as to spray cooling gas to the steel sheet, thereby cooling same; and a moving portion for driving the defect prevention portion such that same moves.

An apparatus for the continuous hot dip coating of a metal strip is provided. The apparatus includes a vessel intended to contain a liquid metal bath, a bottom roller and a displacement casing for the metal strip. The casing includes an upper portion and a lower portion. The lower portion includes a pouring box delimiting at least two liquid metal pouring compartments. Each pouring compartment is inwardly delimited by an inner wall including an upper rim. The casing is provided with the pouring box, is rotatable relative to the metal strip around a first rotation axis and the pouring box is rotatable relative to the upper portion of the casing around a second rotation axis. A method for coating the metal sheet is also provided.

A continuous coating line includes a roll assembly exposed to molten metal. The roll assembly includes a roll rotatable relative to a bearing block. The roll includes a roll portion and a journal protruding from each end of the roll portion. The roll is made from a refractory ceramic material that is resistant to wear, abrasion, and corrosion when the roll is exposed to the molten metal.

Provided is a method of producing a hot-dip metal coated steel strip with which a hot-dip metal coated steel strip of high quality can be produced by sufficiently suppressing edge overcoating. The method comprises spraying gas from a pair of gas wiping nozzles 20A and 20B onto a steel strip S while being pulled up from a molten metal bath 14, to adjust a coating weight of molten metal on both sides of the steel strip S, wherein a pair of baffle plates 40 and 42 are respectively placed outside of both transverse edges of the steel strip, and a height B of a lower end of each of the pair of baffle plates 40 and 42 with respect to a bath surface of the molten metal bath is set to +50 mm or less, where an upper side in a vertical direction is positive.

A method for producing a metallic coated steel sheet is provided. The method includes continuously annealing a steel sheet in a continuous annealing furnace and hot dip coating the steel sheet.

Disclosed is a method of producing a hot-dip metal coated steel strip capable of sufficiently suppressing generation of bath wrinkles and producing high-quality hot-dip metal coated steel strip at low cost. The disclosed method of producing a hot-dip metal coated steel strip includes: blowing a gas from a pair of gas wiping nozzles 20A and 20B to a steel strip S while being pulled up from a molten metal bath 14 so as to adjust a coating weight of molten metal on both sides of the steel strip S, in which each of the gas wiping nozzles 20A and 20B includes an injection port portion that is installed downward with respect to a horizontal plane such that an angle formed by the injection port portion and the horizontal plane is 10° or more and 75° or less, and has a header pressure below 30 kPa.

An equipment for the continuous hot dip-coating of a metal strip including an annealing furnace, a tank containing a liquid metal bath, a snout connecting the annealing furnace and the tank, through which the metal strip runs in a protective atmosphere and the lower part of the snout, the snout tip, is at least partly immersed in the liquid metal bath in order to define with the surface of the bath, and inside this snout, a liquid seal and a separate overflow attached/hold to the snout through fixings, the overflow including at least one tray, placed in the vicinity of the strip when entering the liquid metal bath and encompassed by the liquid seal.

A method for rinsing an overflow chamber at the bath-side end of a snout of a device for hot-dip coating a metal strip is presented. The snout guides the metal strip in a protective gas atmosphere before the metal strip is coated with a metal melt. A rinsing cycle is carried out in the overflow chamber of the snout by feeding metal melt from the molten bath into the overflow chamber and at the same time, sucking and pumping said melt out of the overflow chamber back into the molten bath. This rinsing cycle can be performed even when the snout has been retracted from the melt by supplying the melt from the molten bath to the overflow chamber with a delivery pump.

The present invention relates to an apparatus and a method of manufacturing a hot dipped galvanized steel sheet that is excellent in corrosion resistance and has no linear defects, thereby being available for automobile bodies, household appliances, construction materials, and the like which need aesthetic surfaces. The apparatus for manufacturing a hot dipped galvanized steel sheet includes: a plating pot filled with a galvanizing bath for coating of a steel sheet; a sink roll; a wiping device adjusting the thickness of the coating on the steel sheet; a top roll; an oxidation process chamber; and an air cooling device. According to the present invention, after an excess molten coating solution attached to the steel sheet is evenly removed, an oxide film is made to be 0.1 m to 0.3 m thick before a coating layer starts to solidify. Thus, linear defects can be prevented.

Provided is a method for producing a hot-dip Al-based metal-plated steel sheet including a plated layer having a surface on which fine spangle are stably formed. A method for producing a hot-dip Al-based metal-plated steel sheet, includes a composition adjusting step of adding a B-containing master alloy so as to adjust a composition of an Al-based hot-dip plating bath (3) containing aluminum as a main component, the composition being adjusted so that the Al-based hot-dip plating bath has a B concentration of not less than 0.005 mass % and a K concentration of more than 0 mass % and less than 0.0005 mass %, the K concentration being reduced in the Al-based hot-dip plating bath by supplying gas into the Al-based hot-dip plating bath so as to remove a suspended matter on a surface of the Al-based hot-dip plating bath.