THE WATER FOR REMOVING THE FILM OF OXIDE OR RUST ON METAL, AND THE METHOD FOR REMOVING THE FILM OF OXIDE OR RUST ON METAL USING THIS WATER

摘要

TECHNICAL FIELD The present invention relates to the use of acidic water obtained by electrolysis as an oxide film or rust removal water on a metal surface, and a method for removing an oxide film or rust on a metal surface using the water.;The present invention is water obtained by electrolysis of raw water containing sulfate ions or raw water added with a mixture containing sulfate or sulfate to raw water, wherein the concentration of sulfate ion is 20 to 20000 mg / l, and the pH of the water is 0.5. ~ 4.0, residual chlorine concentration of 10 mg / l or less, redox potential of 300 to 1150㎷, sulfate ion concentration of 30 to 30000 mg / l, chloride ion concentration of 3/4 or less of sulfate ion concentration or 50 mg / l Hereinafter, the present invention relates to an oxide film or rust removal water (hereinafter referred to as "oxide removal water") of a metal, which has an electrical conductivity of 10 S / m or less.