| 摘要 |
PURPOSE:To prevent the pitting corrosion of an Al material in a corrosive environment by adding a specified amt. of F ions to the environment. CONSTITUTION:When an Al or Al material is in a corrosive environment in which the material is exposed to cooling water contg. inevitably Cl ions in a heat exchanger or the like, >=about 0.1ppm, preferably >=about 10ppm F ions are added to the cooling water. The desirable pH of the cooling water contg. F ions is about 5-10. The pitting corrosion potential of the Al material is made remarkably higher than natural potential, critical electric current causing pitting corrosion is increased and the pitting corrosion of the Al material is prevented. |
