METHOD FOR TREATING THE SURFACE OF METALS

A surface treatment method of a metal body is provided to remove various problems such as a safety problem of an operator, environmental pollution, noise pollution, and impossible pre-treatment of a complicate shaped object generated during pre-treatment by a conventional sand blasting method, and certainly adhere a painting layer onto a surface of the metal body while securing corrosion resistance thereon. In a method for treating a surface of a metal body, which method comprises forming a coating layer on the surface of the metal body to maintain coating adhesion between the surface of the metal body and the painting layer before forming a painting layer on the surface of the metal body, the method is characterized in that: the coating layer is formed in an oxide form on the surface of the metal body by dipping electrodes opposite to the metal body into an electrolyte such that the electrodes are spaced from each other, and conducting the electrodes such that different polarities are applied to the electrodes, thereby applying an electric current to the electrodes such that a current waveform of a forward direction and a current waveform of a reverse direction are alternated with the passage of time; and the coating layer formed on the surface of the metal body has a thickness of 10 mum or less.