Abstract: Provided is a galvanized steel sheet having excellent spot weldability; and a method for producing same. The galvanized steel sheet includes a base steel sheet and a zinc-based plating layer formed on the base steel sheet, wherein the surface layer of the base steel sheet may have a decarburization rate of at least 30% as represented by equation 1. [Equation 1]: Decarburization rate (%) of surface layer=(1?average carbon concentration in surface layer/bulk carbon concentration)*100, where the surface layer refers to a region extending to a depth of 35 ?m from the surface of the base steel sheet.

Abstract: An air knife includes: a nozzle main body provided so as to inject gas in response to the width of the steel plate; a nozzle lip installed on at least one of the upper section and the lower section of an outlet of the nozzle main body and extending inclinedly so that the injection cross-sectional area of the gas becomes narrow; and at least one moment generation unit, provided at one side of the nozzle lip, for generating a rotation moment so that the nozzle lip is curved in the width direction of the steel plate and a gap between other nozzle lips varies.

Abstract: An air knife includes: a nozzle main body provided so as to inject gas in response to the width of the steel plate; a nozzle lip installed on at least one of the upper section and the lower section of an outlet of the nozzle main body and extending inclinedly so that the injection cross-sectional area of the gas becomes narrow; and at least one moment generation unit, provided at one side of the nozzle lip, for generating a rotation moment so that the nozzle lip is curved in the width direction of the steel plate and a gap between other nozzle lips varies.

Abstract: There are provided an electromagnetic wiping device, a plated steel sheet wiping apparatus including the electromagnetic wiping device, and a method for manufacturing a plated steel sheet. A portion of a plating layer of a steel sheet having passed through a plating bath is preliminarily removed at least in an edge region of the steel sheet, and a gas wiping operation is performed. Therefore, overplating is prevented at least in the edge region of the steel sheet. In addition, since the load of gas wiping can be reduced while maintaining the line speed of the steel sheet, the quantity of scattered particles and the formation of dross can be reduced for improving the plating quality of the steel sheet and the productivity of a manufacturing process.

Abstract: Provided is a steel strip stabilizing apparatus which allows shape correction and vibration suppression in a steel strip, particularly, plated steel strip, in a non-contact manner. The steel strip stabilizing apparatus includes an apparatus support body disposed on at least one side of a traveling steel strip and a steel strip stabilizing unit comprising a magnetic field generating pole disposed on the apparatus support body to face the steel strip and a pole expansion part configured to provide steel strip attraction force to a steel strip-side end of the magnetic field generating pole so as to allow shape correction or vibration suppression in the steel strip.

Abstract: Provided is a steel strip stabilizing apparatus which dampens vibrations of a plated steel strip in a non-contact manner or corrects the shape of the plated steel strip. The steel strip stabilizing apparatus comprises: a plurality of steel strip damping means arranged on at least one side of a steel strip undergoing processing in a direction there towards so as to damp vibrations in the steel strip; and a damping means moving unit connected to the steel strip damping means to move at least a portion of each of the steel strip damping means in a widthwise direction with regard to the steel strip corresponding to the width of the steel strip. According to the present invention, (unit) damping means are movable in the widthwise direction with regard to the steel strip, thus improving the vibration damping properties, the steel strip curvature correcting properties and the plated quality of the steel strip.

Abstract: Provided is an apparatus for efficiently removing a pollutant source in a snout of a steel plating line such as a steel galvanizing line. The pollutant removing apparatus includes at least one pollutant collecting member connecting to a snout between a heating furnace and a plating tank, and a contact-free inducer varying magnetic field within the snout to forcibly guide, without contact, a pollutant source of a steel plate or a processing unit to the pollutant collecting member.

Abstract: Provided are an electromagnetic wiping device for controlling the amount of coating of a steel sheet, a steel sheet wiping device including the same, and a method for manufacturing the steel sheet. The present invention can prevent overcoating at least at the edge of the steel sheet by removing a coating layer of at least an edge part of the steel sheet passing through a plating bath by using electromagnetism and forming the gas wiping, and can reduce gas wiping capabilities while maintaining the line speed of the steel sheet so as to reduce the amount of scattered material or dross due to the scattered material, thereby ultimately improving the coating quality and the productivity of the steel sheet.

Abstract: Provided is a steel strip stabilizing apparatus which allows shape correction and vibration suppression in a steel strip, particularly, plated steel strip, in a non-contact manner. The steel strip stabilizing apparatus includes an apparatus support body disposed on at least one side of a traveling steel strip and a steel strip stabilizing unit comprising a magnetic field generating pole disposed on the apparatus support body to face the steel strip and a pole expansion part configured to provide steel strip attraction force to a steel strip-side end of the magnetic field generating pole so as to allow shape correction or vibration suppression in the steel strip.

Abstract: Provided is a steel strip stabilizing apparatus which dampens vibrations of a plated steel strip in a non-contact manner or corrects the shape of the plated steel strip. The steel strip stabilizing apparatus comprises: a plurality of steel strip damping means arranged on at least one side of a steel strip undergoing processing in a direction there towards so as to damp vibrations in the steel strip; and a damping means moving unit connected to the steel strip damping means to move at least a portion of each of the steel strip damping means in a widthwise direction with regard to the steel strip corresponding to the width of the steel strip. According to the present invention, (unit) damping means are movable in the widthwise direction with regard to the steel strip, thus improving the vibration damping properties, the steel strip curvature correcting properties and the plated quality of the steel strip.

Abstract: Provided is an apparatus for efficiently removing a pollutant source in a snout of a steel plating line such as a steel galvanizing line. The pollutant removing apparatus includes at least one pollutant collecting member connecting to a snout between a heating furnace and a plating tank, and a contact-free inducer varying magnetic field within the snout to forcibly guide, without contact, a pollutant source of a steel plate or a processing unit to the pollutant collecting member.

Abstract: A magnetic bearing device includes a magnet generating a magnetic field at a protrusion formed toward a roll shaft, and a body portion supporting the magnet in one direction. The roll shaft is supported while an air gap is formed between the roll shaft and the protrusion, and both sides of the protrusion are rounded.

Abstract: A magnetic bearing device includes a magnet generating a magnetic field at a protrusion formed toward a roll shaft, and a body portion supporting the magnet in one direction. The roll shaft is supported while an air gap is formed between the roll shaft and the protrusion, and both sides of the protrusion are rounded.