Provided is a hot-dip plating method that achieves good plating wettability between a metal material and a hot-dip plating bath and that makes it possible to reduce the amount of consumed energy as compared to conventional techniques. In a plating step included in the hot-dip plating method, vibration is applied to a hot-dip plating bath such that the ratio of the average sound pressure level (excluding noise) over ranges each lying between sound pressure peaks at harmonic frequencies of a fundamental frequency to the average sound pressure level (excluding noise) over the measured frequency range in an acoustic spectrum is greater than 0.2.

A component for a hot-dip metal plating bath includes a base material and a thermal spray coating disposed to cover a surface of the base material. The base material includes ferritic stainless steel that contains: C: 0.10% to 0.50% by mass; Si: 0.01% to 4.00% by mass; Mn: 0.10% by mass to 3.00% by mass; Cr: 15.0% to 30.0% by mass; a total of Nb, V, Ti, and Ta: 0.9% by mass to 5.0% by mass; and a balance of Fe and unavoidable impurities. The ferritic stainless steel includes a microstructure that includes a ferrite phase as a main phase and a crystallized carbide, an area fraction of a Nb carbide, a Ti carbide, a V carbide, a Ta carbide, and a composite carbide thereof to the crystallized carbide of 30% or more. The hot-dip metal plating bath contains 50% by mass or more of Al.

A correction apparatus for correcting the planarity of a metal strip advancing into a coating system for coating said metal strip with a layer of molten metal, said apparatus comprising

a bridle roll, which modifies the feeding direction of the metal strip exiting an annealing furnace;

only one sink roll, arranged downstream of said bridle roll and inside a tank adapted to contain a bath of said molten metal;

a correction device for correcting the planarity of the metal strip arranged between said bridle roll and said sink roll;

wherein said correction device comprises at least two motorized rolls;

wherein a first motorized roll of said at least two motorized rolls is distal from said bridle roll in a fixed position with respect to a feeding path of the metal strip, said first motorized roll being arranged on a first side of said feeding path;

wherein said bridle roll is also arranged on said first side;

and wherein a second motorized roll of said at least two motorized rolls is proximal to said bridle roll and movable along the direction of the strip thickness, said second motorized roll being arranged on a second side, opposite to the first side, of said feeding path.

A gas wiping nozzle configured to blow wiping gas onto a metal strip includes a first nozzle member and a second nozzle member provided to face each other, in which a slit as a gas blowing port is formed to extend in a length direction between end portions of the first nozzle member and the second nozzle member on the metal strip side; and a shim member configured to adjust a gap of the slit in a width direction orthogonal to the length direction, wherein the shim member is made of a ceramic material or a carbon material, each of the first nozzle member and the second nozzle member has a groove portion, and the shim member is fitted into both of the groove portions of the first nozzle member and the second nozzle member and fixes the first nozzle member and the second nozzle member.

A method for producing a hot-dip galvanized steel sheet includes supplying humidified gas to the soaking zone 12 in a manner such that: in passes in which the steel sheet moves upward, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions higher by 1.0 m or more and 5.0 m or less than the centers of lower hearth rolls 54 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone; and in passes in which the steel sheet moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions lower by 1.0 m or more and 5.0 m or less than the centers of the upper hearth rolls 52 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone.

A hot dip coating device to provide a metal coating on a moving metal sheet, containing a liquid bath of metal coating material in use. The metal coating material on the moving metal sheet in use, including a container for the liquid bath, a guide or sink roll in the container below liquid bath surface level in use to guide the moving metal sheet through the bath, and a gas knife, above the liquid bath in use, having an outlet to project wiping gas on the metal coating on the metal sheet. At least one supporting roll with the guide or sink roll in use influence metal sheet shape in its width direction at the gas knife location. The one supporting roll is above liquid bath surface level to operate on the metal sheet before the metal sheet enters the bath. A method for use of the device.

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 μm to 0.3 μm thick before a coating layer starts to solidify. Thus, linear defects can be prevented.

A method for monitoring a manufacturing of a metal product, the metal product being manufactured according to a manufacturing process, is implemented by an electronic monitoring device. This method includes acquiring (100) a measured value of at least one representative parameter, each representative parameter being a parameter relating to the metal product or a parameter relating to the manufacturing process, determining (130) a status of the metal product among a compliant status and an analysis status, depending on the at least one acquired value and on at least one target, and when the determined status is the analysis status, computing (150) a corrective action to be applied to the product, among a set of corrective actions and depending on the at least one acquired value, the set of corrective actions including a product repair, a product downgrading, a product expertise and a product acceptance.

A continuous coating line includes a snout assembly exposed to molten metal. The snout assembly includes a snout tip positioned about a steel strip that is immersible in the molten metal to provide a seal around the steel strip during entry into the molten metal. The snout tip includes a refractory material that is resistant to wear, abrasion, and corrosion when the snout tip is exposed to the molten metal.

An apparatus for cooling a steel sheet includes: an apparatus body provided spaced apart from a steel sheet in the conveying path of the steel sheet; and a cooling unit provided in the apparatus body to supply a cooling fluid. The apparatus body includes: a first edge body that faces a first edge portion extending a certain distance from one side end of the steel sheet toward the center of the steel sheet; and a second edge body that faces a second edge portion extending a certain distance from the other side end of the steel sheet toward the center of the steel sheet. The first and second edge bodies may have stepped cross-sections in a direction perpendicular to the conveying direction of the steel sheet.