METHOD AND APPARATUS FOR PRODUCING METALLIC MATERIAL AT LEAST PARTLY COVERED WITH PHOSPHATE CHEMICAL CONVERSION FILM

摘要

PROBLEM TO BE SOLVED: To provide a technique whereby wastewater appearing in a chemical conversion treatment is confined in a closed system, enabling an environmental pollution countermeasure to be devised, and a phosphate chemical conversion film excellent in corrosion resistance and adhesion to a coating film is formed even inside the bag section of a product having a bag section structure (e.g. an automotive body) without introducing a special equipment modification. SOLUTION: The method for producing a metallic material at least partly covered with a phosphate chemical conversion film comprises a surface adjustment step followed by a chemical conversion treatment step. In the chemical conversion treatment step, a metallic material is treated with a phosphate chemical conversion treatment liquid containing an oxidant with an oxidizing power capable of maintaining ferrous ions in the liquid and an oxidant with an oxidizing power capable of oxidizing ferrous ions into ferric ions. In the surface adjustment step, the surface of a metallic material is adjusted with a surface adjustment liquid which contains a phosphate compound having a particle size of 5μm or less and containing at least one metal selected from among divalent and trivalent metals. COPYRIGHT: (C)2004,JPO