PROCESS OF PICKLING OF METAL PRODUCTS Russian patent published in 2001 - IPC

FIELD: pickling of articles from metals and alloys carrying metal of titanium group. SUBSTANCE: pickling bath contains hydrofluoric, sulfuric, hydrochloric, phosphoric or formic acid. Oxygen, ozone, hydrogen peroxide, carbamide peroxide, per acid or persalt is injected as oxidizing agent into it. Article to be pickled is immersed. Peroxide compound carrying metal in highest degree of oxidation is formed as result of interaction of metal with oxidizing agent. This compound is utilized as pickling agent. Formation of compound is controlled by measurement of redox potential and its adjustment in interval from potential of formation of peroxide compound to value below potential of passivation of metal. Vanadium, zirconium, titanium, tantalum or uranium are elements of titanium group. EFFECT: raised pickling kinetics, high quality of surface of metal articles. 7 cl, 1 tbl