SOLUTION AND PROCESS FOR ETCHING STAINLESS STEEL Russian patent published in 1997 - IPC

FIELD: chemical treatment of metals; metallurgical and other industries. SUBSTANCE: claimed solution comprises iron (II) ions, iron (III) ions, hydrogen peroxide source, organic acid that does not oxidize iron to maintain the ratio of iron (II) ions to iron (III) ions at 10/90 to 40/60. The organic acid is compound of formula: R-(COOH)_n wherein n is 1-3, R is hydrogen, C₁-C₄ alkyl or hydroxyalkyl group, C₆-C₁₄-aryl, aralkyl or alkylaryl group, formic , acetic, propionic, butanic, lactic, benzoic, phthallic or naphthoic acid unsubstituted or substituted by C₁-C₄ alkyl group or halogen. The hydrogen peroxide source is peracid, e.g. peracetic, perboric, perbenzoic, persulfuric, perphosphoric, iodic, perphthallic acid or acid which is homologeous with organic acid; peracid salt, e.g. sodium peroxycarbonate or magnesium peroxyborate; organic peroxide, e.g. urea peroxide. The claimed process for etching stainless steel comprises treatment with acid solution containing iron (II) ions iron (III) ions and hydrogen peroxide source at 10-90 C. EFFECT: more efficient etching process. 10 cl