JPS5921702B2 - Metal parts surface coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a simple coating method that is used for repairing surface defects of metal products and structures, or for local surface coating treatment, and is capable of forming a strong coating with a uniform thickness.

When welding metal products or structures that have been coated with galvanizing or other coating treatments, the welded area and the surrounding plating will burn out.

Further, even during use, peeling or chipping of the plating layer may occur, and sufficient corrosion resistance may not be exhibited. As a repair method for these, there is a method of using powder of a metal surface coating composition that can be easily welded to the surface of metal parts by heating with gas, etc.・A method was used in which the coating was applied using a method such as ke, and then heated.

However, this method has drawbacks such as the inability to maintain a constant thickness of the applied powder and the inability to obtain a thick coating film. In particular, when the material to be treated is standing upright, the applied composition will sag due to gravity. Furthermore, since the heating gas comes into direct contact with the coating composition, there is a disadvantage in that an unfavorable atmosphere or temperature unevenness is generated for plating. The present invention aims to eliminate such drawbacks and to make it possible to easily and firmly coat metal coatings of uniform thickness or even thick coatings on coating defects on the surfaces of all metal parts. This method was proposed for the purpose of coating a metal component by applying a film-like material on one side of which a coating metal composition powder is coated to a predetermined thickness so that the composition adheres to the surface of the metal member to be coated, and then heating it. Provided is a method for coating the surface of a metal member, characterized in that the composition is welded onto the surface of the metal member.

The method of the present invention will be explained in detail with reference to the drawings.

In FIG. 1, 1 is a paste made by mixing powder of a metal coating composition with water or an organic substance, and this is applied to a flexible thin plate 3 to a predetermined thickness, and 2 is a paste. This is an adhesive applied to both ends of the thin plate 3. Note that the thin plate 3 is preferably flexible so as to conform to the shape of the metal surface to be coated. FIG. 1 shows a piece of the long metal surface coating tape Al produced in this way, and FIG. It shows the state where it is attached to the burnt part □ of the galvanized plate. The pasting procedure is to place the tape A so that the coating composition 1 is in close contact with the burnt part 1, and to fix it by pressing the adhesive 2 applied to both ends onto the steel pipe 5. Figure 3 shows galvanized coating 4a.
Tape A shows a state where the metal surface coating treatment membrane tape A is pasted to repair a part of the outer surface of the steel pipe 5a coated with the coating, that is, the part 8a where the plating coating 4a has peeled off.
One side of the paper is shown cut away.

By heating the tape A with, for example, a gas burner or the like in the state shown in FIGS. 2 and 3 and depositing the coating composition 1 on the steel pipe 5a, burnt or peeled portions of the plating film can be easily repaired. be able to. Here, the six-metal surface coating composition may be a mixture of zinc, tin-zinc hexachloride, ammonium chloride, cadmium chloride, stannous chloride, etc., a soldering metal powder such as Ni wax, Ag wax, or autoclave, depending on the object to be coated. Thin alloy powder or the like can be used, and in short, any material that easily adheres to the metal surface by heating with gas or the like can be used. Which one is suitable for applying? Examples of alloys include Ni-Cr-Sr alloy CO-Ni-Cr-
Examples include MO alloys. In addition, the material of the coating composition powder and the film-like body to which the adhesive is applied should be flexible so that it can follow the shape of the metal surface to be coated, such as paper, resin film, metal foil, etc. (e.g. aluminum foil)
Among these, materials that are easily burned out by heating, such as paper, or materials that are easily separated from the coating composition after heating are preferred in terms of ease of handling. The film-like material prevents the heating gas flame from coming into direct contact with the coating composition6, and thus enables uniform heating of the coating composition; Even if it is, the coating composition will melt and adhere to the metal surface before it burns out, and even if the coating composition is then directly hit by flame, there is no need to worry about the force of scattering or local heating of the composition. Further, even if the film-like body is not burnt out during heating, it can be removed as necessary after the coating treatment. The coating composition is made into a slurry by mixing water or an organic substance and is applied to the film-like body, but after application, the film-like body absorbs water and becomes a dry powder film. It will be constructed in

Therefore, particularly suitable materials for the membrane-like body are those that have water absorbency and water absorbability, such as paper that satisfies these conditions. When the method of the present invention is carried out as a local coating treatment on the surface of a metal product or structure, cleaning treatment such as degreasing (6) with a grinder and sanding is performed before the coating treatment in order to improve the adhesion of the film-like body. It is good to apply
In order to further improve the adhesion, water or an adhesive may be applied to the metal surface, or may be applied to the film-like body before being pasted.

Note that it is desirable to use an adhesive that does not generate toxic gas during heating. Next, an example will be described in which the method of the present invention is applied to a burnt part due to back welding of a galvanized steel pipe (60j11 (PX8J!l thickness)).

First, the coating composition powder was 40% zinc and 15% tin.
A mixture of 23% zinc chloride and 22% ammonium chloride was used, and approximately 10% water by weight was added to the mixture to form a paste.
Next, apply the paste-like mixture evenly to a tape-shaped paper with adhesive to a thickness of one inch to make a covering tape as shown in Fig. The tape and its surrounding plating were brought into close contact with the burnt part, and the adhesive-applied parts at both ends of the tape were attached to a steel pipe and then heated with a 2-oxygen-acetylene flame. As a result, a film almost similar to the zinc film formed by the IIC fusion galvanizing method was formed on the part where the zinc plating was burnt out.

That is, the coating surface was smooth and the peel strength was equivalent to that obtained by the post-melting plating method. It is possible that the coating composition may melt and generate gas when heated, but this can be prevented by using a tape, thin plate, or other membrane-like material with holes for gas release, or fabric or paper. A material with good gas permeability, such as, may be used. As described above, the method of the present invention can easily repair defects in the plating film by adhering to the surface of metal-plated metal products or structures, or perform local coating treatment, and the formed film can also be applied to the surface. It is useful because it has advantages comparable to the fusion plating method in terms of its beauty, uniformity of film thickness, adhesiveness, etc.

[Brief explanation of drawings]

Figure 1 is a perspective view showing a cross-section of the coating tape used in the method of the present invention. Figure 2 is a partial view of the coating tape applied to the defective part of the plating film due to the adhesion of a steel pipe using the method of the present invention. Fig. 3 is a partially cut perspective view showing a state in which the coating tape is coated on the plating-peeled portion of a steel pipe by the method of the present invention. A...Coating tape, 11a...Coating composition, 2,2a...Adhesive, 3,3a...
... Thin plate, 4,4a... Galvanized coating,
5, 5a... Steel pipe, 6... Arbitrary connection part, 7
... Burnt part, 8a ... Peeling part of galvanized film.

Claims (1)

[Claims] 1 A film-like body coated with coating metal composition powder to a predetermined thickness on one side is attached so that the same composition adheres to the surfaces to be coated of all metal members, and then heated to coat the same composition. A metal member surface coating method characterized by welding to the surface.