摘要 |
Corrosion is inhibited on a metallic surface by placing it as the cathode in an aqueous acid electrolyte saturated with a chromate, e.g. of Ca, Sr, Ba, Zn, Cd, Cu, Al, Fe (ferric) or Pb, and passing D.C. through the electrolyte to deposit a chromate on the surface. Preferably the electrolyte is a solution of a chromate in chromic acid. The surface to be treated may be Fe, Al, Mg, Zn or alloys thereof such as steel, or a Zn-(galvanized), Cd- or Sn-plated article; the anode may be of Pb, Pt or C. |