Film-forming structure on work and film-forming method on work

Abstract

A film-forming structure and a film-forming method on a work include closely depositing a thin primary film on a work, the primary film being a suboxide or an oxide including metal and is soft and has insulation properties and corrosion resistance. The primary film is porous film. The work is integrated with the primary film to prevent the primary film from peeling, and thereby improving the workability. The thin secondary film such as a coating is attached to the primary film closely, thereby reducing the amount of paint used. The primary film is integrated with the secondary film to prevent the secondary film from peeling, improving the workability after formation of the secondary film, and thereby forming the primary and secondary films rationally.

Description

TECHNICAL FIELD[0001]The present invention relates to a film-forming structure and a film-forming method on a work that include closely depositing a thin primary film on a work, the primary film being a suboxide or an oxide which is soft and has insulation properties and corrosion resistance. The work is integrated with the primary film to prevent the primary film from peeling, and thereby improving the workability. A thin secondary film such as a coating is attached to the primary film closely, thereby reducing the amount of paint used. The primary film is integrated with the secondary film to prevent the secondary film from peeling and cracking, improving the workability after formation of the secondary film, and thereby forming the primary and secondary films rationally.BACKGROUND ART[0002]Since plating is a metal film, pinholes generated by electrolysis are unavoidable, and thus leading to a problem of corrosion due to potential difference in different metals. In coating, since ...

AI Technical Summary

Benefits of technology

The invention describes a method for improving insulation and corrosion resistance of a workpiece by depositing a porous primary film made of metal suboxide or oxide on the surface of the workpiece. This primary film acts as a layer for easier adhesion of a secondary film which can prevent peeling and cracking. The porous structure of the primary film also enhances adhesion between the primary and secondary films. Additionally, the primary film can improve the adhesion of coatings, such as paints, to the workpiece. If the suboxide is chromium suboxide or chromium oxide, the surface of the film has minute irregularities that further improve adhesion of the secondary film. The soft and flexible primary film improves workability, insulation, and corrosion resistance of the workpiece.

Problems solved by technology

Since plating is a metal film, pinholes generated by electrolysis are unavoidable, and thus leading to a problem of corrosion due to potential difference in different metals.

In coating, since rust on metal surfaces generated by oxygen permeation is unavoidable, thick coatings are formed to deal with the problem.

Then the primer coating and the top coating are required, which leads to a time consuming process.

Further, since the coating becomes thick, it tends to peel off, which leads to peeling and cracking during a subsequent processing.

Thus, the coated steel plate has a poor workability.

Since forming a uniform chromate film is difficult, a surface conditioning is required, in which an acid surface conditioner is applied to an original plate for coating before a chromate treatment.

This leads to a time-consuming process.

However, the above method can only be applied to certain types of hot-dipped galvanized steel plate.

Surface condition of the coated original plate is too complicated, which also makes preparation of the surface conditioner complicated.

Further, the coating process is still complicated, unproductive, and inefficient.

However, the above method takes time for treatment since the chromium plating and the chromium oxide are deposited separately.

Thus, corrosion due to potential difference between the chromium oxide and chromium steel plate tends to occur.

Further, the increase in hardness of the chromium oxide leads to a poor workability after formation of the film.

When the coated product is bent, the coating tends to peel off and crack.

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