Abstract: A pass roll for a hot-dip galvanized steel sheet manufacturing facility, the pass roll includes: a roll body; and a heat-resistant felt layer covering the roll body, wherein the heat-resistant felt layer has a thermal decomposition temperature of 420° C. or higher and has a surface hardness evaluation index at 400° C. of more than 0.11 ?m/N.

Abstract: A pass roll for a hot-dip galvanized steel sheet manufacturing facility, the pass roll includes: a roll body; and a heat-resistant felt layer covering the roll body, wherein the heat-resistant felt layer has a thermal decomposition temperature of 420° C. or higher and has a surface hardness evaluation index at 400° C. of more than 0.11 ?m/N.

Abstract: The present invention provides a cooling device for a hot-dip plating device provided on an upper side of a plating thickness control device in a conveyance route of a hot-dip plated steel sheet that is conveyed from a plating bath in a vertically upward direction. The cooling device includes: a main cooling device that vertically sprays a main cooling gas to the hot-dip plated steel sheet; and a preliminary cooling device that is provided in a preliminary cooling section between the main cooling device and the plating thickness control device in the conveyance route, and sprays a preliminary cooling gas to a plurality of gas collision positions which are set along the preliminary cooling section.

Abstract: The present invention provides a cooling device for a hot-dip plating device provided on an upper side of a plating thickness control device in a conveyance route of a hot-dip plated steel sheet that is conveyed from a plating bath in a vertically upward direction. The cooling device includes: a main cooling device that vertically sprays a main cooling gas to the hot-dip plated steel sheet; and a preliminary cooling device that is provided in a preliminary cooling section between the main cooling device and the plating thickness control device in the conveyance route, and sprays a preliminary cooling gas to a plurality of gas collision positions which are set along the preliminary cooling section.

Abstract: A method for producing a hot dip plated steel sheet, the method controlling a coating weight by injecting a gas toward a surface of a steel sheet from a time when the steel sheet continuously immersed into a plating bath is pulled up from the plating bath to a time when plating metal adhered onto the surface of the steel sheet is solidified, the method includes: setting an oxygen concentration of a bath surface of the plating bath to be more than or equal to 0.05 vol % and less than or equal to 21 vol % when the gas is injected toward the surface of the steel sheet; and setting an oxygen concentration in a space of an end of the steel sheet at a position where the gas collides with the steel sheet pulled up from the plating bath to be more than or equal to 0.05 vol % and less than or equal to 3 vol % when the gas is injected toward the surface of the steel sheet.

Abstract: A gas wiping apparatus includes a pair of wiping nozzles which are disposed so as to face each other and interpose a coated steel sheet therebetween in a thickness direction of the coated steel sheet, and each of which ejects a wiping gas along a width direction of the coated steel sheet; a gas shield plate that is disposed at a position which separates toward an outside from each end portion of the coated steel sheet so that the gas shield plate is interposed between the pair of wiping nozzles; and a side nozzle that ejects a gas to form a gas flow along each surface of the gas shield plate in a direction reverse to a direction in which the coated steel sheet is pulled upward.

Abstract: The present invention provides a high-corrosion-resistance hot-dip galvanized steel sheet having excellent appearance uniformity. The steel sheet includes: a coating layer containing Al: 4 to 22 mass %, Mg: 1 to 6 mass %, and Si: 0.001 to 1 mass %, and a balance being composed of Zn and inevitable impurities formed on a surface, in which at an interface between the coating layer and a base steel sheet, Mg2Si phases and Ca phases each mainly composed of Ca or a Ca compound exist, and at least part of the Mg2Si phases precipitate by using the Ca phases as a nucleus.

Abstract: The present invention provides a hot-dipped steel 1 that demonstrates favorable corrosion resistance and formability, and has a favorable appearance of a plating layer. The hot-dipped steel of the present invention includes a steel substrate formed thereon with an aluminum-zinc alloy plating layer. The aluminum-zinc alloy plating layer contains Al, Zn, Si and Mg as constituent elements thereof and the Mg content is 0.1% to 10% by weight. The aluminum-zinc alloy plating layer contains 0.2% to 15% by volume of an Si—Mg phase, and the weight ratio of Mg in the Si—Mg phase to the total weight of Mg is 3% or more.

Abstract: A gas wiping apparatus includes a pair of wiping nozzles which are disposed so as to face each other and interpose a coated steel sheet therebetween in a thickness direction of the coated steel sheet, and each of which ejects a wiping gas along a width direction of the coated steel sheet; a gas shield plate that is disposed at a position which separates toward an outside from each end portion of the coated steel sheet so that the gas shield plate is interposed between the pair of wiping nozzles; and a side nozzle that ejects a gas to form a gas flow along each surface of the gas shield plate in a direction reverse to a direction in which the coated steel sheet is pulled upward.

Abstract: The present invention provides a high-corrosion-resistance hot-dip galvanized steel sheet having excellent appearance uniformity. The steel sheet includes: a coating layer containing Al: 4 to 22 mass %, Mg: 1 to 6 mass %, and Si: 0.001 to 1 mass %, and a balance being composed of Zn and inevitable impurities formed on a surface, in which at an interface between the coating layer and a base steel sheet, Mg2Si phases and Ca phases each mainly composed of Ca or a Ca compound exist, and at least part of the Mg2Si phases precipitate by using the Ca phases as a nucleus.

Abstract: The present invention provides a hot-dipped steel 1 that demonstrates favorable corrosion resistance and formability, and has a favorable appearance of a plating layer. The hot-dipped steel of the present invention includes a steel substrate formed thereon with an aluminum-zinc alloy plating layer. The aluminum-zinc alloy plating layer contains Al, Zn, Si and Mg as constituent elements thereof and the Mg content is 0.1% to 10% by weight. The aluminum-zinc alloy plating layer contains 0.2% to 15% by volume of an Si—Mg phase, and the weight ratio of Mg in the Si—Mg phase to the total weight of Mg is 3% or more.

Abstract: A method for producing a hot dip plated steel sheet, the method controlling a coating weight by injecting a gas toward a surface of a steel sheet from a time when the steel sheet continuously immersed into a plating bath is pulled up from the plating bath to a time when plating metal adhered onto the surface of the steel sheet is solidified, the method includes: setting an oxygen concentration of a bath surface of the plating bath to be more than or equal to 0.05 vol % and less than or equal to 21 vol % when the gas is injected toward the surface of the steel sheet; and setting an oxygen concentration in a space of an end of the steel sheet at a position where the gas collides with the steel sheet pulled up from the plating bath to be more than or equal to 0.05 vol % and less than or equal to 3 vol % when the gas is injected toward the surface of the steel sheet.