Method for coating steel plate with metal and metal-coated steel plate manufactured using same

Abstract

Provided are a method for coating a steel plate with a metal and a metal-coated steel plate manufactured by the method. The method includes: heating powder of a first metal at a temperature lower than a softening temperature; heating a gas to a temperature of 200° C. to 600° C.; vacuum-ejecting the heated first metal powder together with the heated gas to form a metal coating layer; and forming a plating layer of a second metal on the metal coating layer.

Description

TECHNICAL FIELD[0001]The present disclosure relates to a method for coating a steel plate with a metal and a metal-coated steel plate manufactured by the method, and more particularly, to a method of forming a pore-free coating layer by forming a porous coating layer through a vacuum ejection coating process and then forming a plating layer, and a steel plate on which the pore-free coating layer is formed.BACKGROUND ART[0002]A method of coating with particles may be used as a surface treatment method for coating various materials with various powder materials, and an ejection velocity is guaranteed by a gas pressure difference between a powder carrier gas and a coating portion normally having a boundary at a nozzle. Particle coating refers to coating with particles, and since particle coating is performed as particles having a size of several tens to several hundreds of nanometers (nm) collide with a coating target material, a coating layer is formed at a much higher rate than in ph...

AI Technical Summary

Benefits of technology

The present disclosure describes a method of coating metal powder onto a steel plate using heated gas. This allows for higher efficiency in coating while increasing corrosion resistance without adding excessive gas consumption. The coated steel plate has a layer with no pores, ensuring the functionality of the coating powder.

Problems solved by technology

In this regard, although the vacuum ejection method is economical because of a low amount of gas consumption, the vacuum ejection method results in low coating efficiency (stacking amount / total ejection amount) and is usable for limited coating materials because of a coating temperature substantially close to room temperature and a lower powder particle ejection velocity than that of the spraying method (such as a thermal spraying method or a cold spraying method).

As disclosed in Korean Patent Application No. 2008-0076019, the vacuum ejection method is generally used for coating with a brittle material such as a ceramic material which is pulverized into powder and recombined during coating and is not suitable for coating with a ductile material such as a metal requiring a large amount of energy for plastic deformation.

In addition, although a particle coating method using the spraying method (such as a thermal spraying method or a cold spraying method) has high efficiency in terms of metal powder, since a body in which a coating target member is provided is maintained at atmospheric pressure, high-pressure gas having a pressure of several megapascals (MPa) is used as a powder carrier gas to create a large pressure difference from atmospheric pressure, thereby resulting in a large amount of gas consumption.

In addition, expensive low-density gas such as He or N2 is commonly used to ensure a particle velocity for high-speed collisions with a coating target member maintained at atmospheric pressure.

Furthermore, according to the spraying method, it is necessary to form a thick coating layer having a thickness within the range of several tens to several hundreds of micrometers (μm) because of problems such as coating layer defects and residual stress, and thus it is practically difficult to form a dense thin coating layer having a thickness of several micrometers (μm) to several tens of micrometers (μm) by the spraying method.

In general, according to such particle coating methods for coating with metal powder, pores are formed in a coating layer, and particularly, in the case of coating with a thin film having a thickness of several micrometers (μm) to several tens of micrometers (μm), corrosion factors permeate through such pores, thereby lowering the corrosion resistance of steel plates.

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