METHOD OF DEPOSITION OF CORROSION-RESISTANT COATING ON ARTICLES MADE FROM FERROUS METALS AND ALLOYS Russian patent published in 1999 - IPC

FIELD: surface treatment of metals, more specifically, chemical treatment of metals, in particular, phosphotization; may be used in protection from corrosion of articles made from ferrous metals and their alloys. SUBSTANCE: method involves articles degreasing their washing with cold water and phosphotizing with 30-40-% solution of zinc monophosphate at temperature of 80-90 C. Then articles are washed with hot water and dried. Obtained coating is impregnated with mixture of inhibiting lubricant AMS-3 and liquid preservation lubricant of in ratio 2.5-3.5:1 at temperature of 60-90 C. Before phosphotization article may be pickled in 20-% solution of sulfuric acid, washed in cold ad then in hot water. Articles may be passivated before impregnation of their coating. The method increases corrosion resistance of coating by factor of 4.5-5 and preserves impact strength and moisture resistance to provide for successful of articles made from cold-rolled steel with coating for operation under conditions of corrosive media. EFFECT: increased corrosion resistance. 4 cl, 1 tbl