| 摘要 |
In order to obtain a film having a low electric resistance and a good selective absorption property of solar radiation, good rust proofing and good weldability, a stainless steel is dipped in a chemical conversion bath, in which sodium bichromate or potassium bichromate is mixed with sulfuric acid at a predetermined proportion to one another, in accordance with the method of the present invention. The product film of the present invention comprises metal oxides or metal hydroxides with metal (Fe+Cr) finely dispersed therein. |
