| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, as the defect of austenitic stainless steel, when it is exposed to an environment containing chlorine, chloride or the like, pitting corrosion or abnormal corrosion, and, further, stress corrosion cracking or the like occur by applying a corrosion preventive film having corrosion resistance on the surface as a countermeasure therefor. SOLUTION: A solution obtained by suitably blending and adding hydrofluoric acid or the sodium salt, potassium salt or ammonium salt thereof to one or more kinds of acids other than chloric acid, iodic acid, bromic acid or the like or the water soluble neutral salts thereof is used as an electrolytic solution. The stainless steel to be treted is connected to the anode side of DC or AC/DC superimposed current obtained by superimposing AC on DC or to either electrode of AC, and is dipped into the electrolytic solution in a state where the other electrically conductive counter electrodes are confronted, and power is supplied thereto, and electrolytic treatment is performed, so that a fluorine or fluorine and oxygen-containing film layer is formed on the surface.
|
