METHOD FOR EVALUATING ANTICORROSION AFTER COATING, METHOD FOR MANUFACTURING HIGH INTENSITY STEEL PLATE EXCELLENT IN ANTICORROSION AFTER COATING, AND HIGH INTENSITY STEEL PLATE EXCELLENT IN ANTICORROSION AFTER COATING

• Main Authors: OTSUKA SHINJI, HARADA HIROKI, TAIRA SHOICHIRO
• Format: Patent
• Language: English; Japanese
• Published: 06.11.2014
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide: a method for evaluating anticorrosion after coating, capable of evaluating and determining the anticorrosion after the coating easily, in a short time, and accurately; a method for manufacturing a high intensity steel plate excellent in anticorrosion after coating; and the high intensity steel plate excellent in anticorrosion after coating.SOLUTION: Cathode polarization is performed to each of steel plates before and after chemical conversion treatment, cathod current values of the steel plates and reduction rates of the cathod current values before and after the chemical conversion treatment are obtained, and anticorrosion after coating is determined by the reduction rates. The steel plate having a reduction rate of 70% or more is determined to be excellent in anticorrosion. Moreover, manufacturing conditions of the steel plates are determined on the basis of evaluation results obtained by the above-described manner. 【課題】塗装後耐食性を簡便に、さらに短時間且つ正確に評価、判定できる塗装後耐食性の評価方法および塗装後耐食性に優れた高強度鋼板の製造方法ならびに塗装後耐食性に優れた高強度鋼板を提供する。【解決手段】化成処理前後の各々の鋼板に対してカソード分極を行い、各々のカソード電流値および化成処理前後の前記カソード電流値の減少率を求め、この減少率をもって塗装後耐食性を判断する。減少率７０％以上を塗装後耐食性良好と判断する。また、上記により得られる評価結果をもとに、鋼板の製造条件を決定する。【選択図】なし