METHOD OF REMOVING IRON OXIDES AND HYDROXIDES FROM SURFACE OF STEEL OBJECTS Russian patent published in 1998 - IPC

FIELD: chemical metalworking. SUBSTANCE: process is carried out by treating surface of object with mixture containing, wt %: maleic acid, 0.1-4; sulfomaleic acid, 0.3-10; methyl, mono-C₃-C₄- alkyl, and dihydroxy-C₃-alkyl sulfomaleates, 1.0-20; methyl, mono- C₃-C₄-alkyl, and dihydroxy-C₃-alkyl maleates, 0.1-2.5; methyl and mono-C₃-C₄-alkyl sulfates, 0.1-5.5; and water, the balance. Treatment is effected for 2-11 min at 50-60 C and treated surface is ready to be submitted to subsequent electroplating. EFFECT: increased assortment of steels apt to be treated and increased quality of treated surfaces (reduced loss of metal, excluded overpeckling, increased resistance of treated surface to further oxidation). 1 tbl