COLD ROLLED STEEL SHEET, METHOD FOR PRODUCING COLD ROLLED STEEL SHEET, AUTOMOTIVE MEMBER, AND COLD ROLLED STEEL SHEET PRODUCTION EQUIPMENT

• Main Authors: MASUOKA HIROYUKI, FURUYA SHINICHI, TAIRA SHOICHIRO
• Format: Patent
• Language: English; Japanese
• Published: 11.04.2016
• Subjects: ALLOYS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a cold rolled steel sheet excellent in chemical conversion treatability and further excellent in corrosion resistance after coating, a method for producing the same, and an automotive member.SOLUTION: Provided is a method for producing a cold rolled steel sheet where a steel sheet subjected to continuous annealing after cold rolling is subjected to primary pickling using any of nitric acid, hydrochloric acid, hydrofluoric acid, sulfuric acid and acid obtained by mixing two or more kinds thereamong, is then subjected to secondary pickling using hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, citric acid and the other nonoxidizing acid, and is further subjected to neutralization treatment using an alkali solution with a pH of 9.5 or higher by sodium hydroxide or the like.SELECTED DRAWING: None 【課題】化成処理性に優れるとともに、塗装後耐食性にも優れる冷延鋼板とその製造方法、ならびに自動車部材を提供する。【解決手段】冷間圧延後連続焼鈍した鋼板に対して、硝酸、塩酸、フッ酸、硫酸およびそれらを２種以上混合混合した酸のいずれかを用いて一回目の酸洗を行い、次いで、塩酸、硫酸、リン酸、ギ酸、酢酸、クエン酸その他等の非酸化性の酸を用いて二回目の酸洗を行い、さらに水酸化ナトリウム他等によるｐＨ９．５以上のアルカリ性溶液を用いて中和処理を行う冷延鋼板の製造方法。【選択図】なし