METHOD FOR EVALUATING CORROSION RESISTANCE OF TRIVALENT CHROMIUM CHEMICAL CONVERSION COATING

• Main Author: TSUCHIYA NAOHISA
• Format: Patent
• Language: English; Japanese
• Published: 18.10.2018
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To more easily evaluate the corrosion resistance of a trivalent chromium chemical conversion coating formed on the surface of a housing constituted of metal in a nondestructive manner.SOLUTION: A method for evaluating the corrosion resistance of a trivalent chromium chemical conversion coating comprises: a step S102 of contacting a region to be evaluated for evaluating a region having the trivalent chromium chemical conversion coating of a housing to a treatment solution consisting of an electrolytic aqueous solution (the second step); a step S103 of setting the potential of a reference electrode electrically connected to the treatment solution to 0 in the state of contacting the region to be evaluated to the treatment solution to measure a potential variation between the housing and the reference electrode for a predetermined time (the third step); and a step S104 of evaluating the corrosion resistance of the trivalent chromium chemical conversion coating on the basis of the measured potential variation(the fourth step).SELECTED DRAWING: Figure 1 【課題】金属から構成された筐体の表面に形成した三価クロム化成皮膜の耐食性が、より容易に非破壊で評価できるようにする。【解決手段】ステップＳ１０２で、筐体の三価クロム化成皮膜を形成した領域の評価を対象とする評価対象領域を、電解質の水溶液からなる処理液に接触させる（第２工程）。ステップＳ１０３で、評価対象領域が処理液に接触している状態で、処理液に電気的に接続している照合電極の電位を０として、筐体と照合電極との間の電位の変化を所定時間測定する（第３工程）。ステップＳ１０４で、測定された電位の変化をもとに三価クロム化成皮膜の耐食性を評価する（第４工程）。【選択図】 図１