| 摘要 |
<p>A method and a combined agent for surface treatment of metals, such as aluminium and zinc, by means of achieving an anti-corrosive surface layer on the metal surface. The method comprises exposure of the metal surface in a pre-treatment step and subsequent surface treatment for obtaining said anti-corrosive surface layer on the metal surface. The surface treatment is performed in two steps; in the first step through contact with a water solution containing sulphuric acid and an oxidation agent for the acid, such as alkali metal permanganate or ammonium persulphate; in the second step through contact with a water solution containing an alkali metal carbonate and an alkali metal permanganate. Hereby, a passivating surface is obtained on the metal surface, consisting of the elements manganese, oxygen, sulphur and carbon.</p> |
