METHOD OF PICKLING STAINLESS STEEL Russian patent published in 1999 - IPC

FIELD: metallurgy; may be used in pickling of stainless steel. SUBSTANCE: stainless steel to be pickled is placed into bath with temperature maintained from 30 to 70 C and having the following initial composition, g/l: H₂SO₄, at least 150; Fe³⁺, at least 15; HF, at least 40; H₂O₂ (added with known stabilizers), 1-20; wetting agents; polishing agents; inhibitors of acid corrosion. Supplied continuously to bath is air with flow rate of at least 3 cu.m/h per cu.m of bath and amount of stabilized H₂O₂ regulated to produce bath redox potential equal to or above 250 mV. EFFECT: reduced expenditures; improved ecology, and increased quality of pickling. 11 cl, 3 dwg, 10 tbl