HIGH SPEED PICKLING TREATMENT METHOD OF STAINLESS STEEL STRIP

PURPOSE:To provide a high efficient descaling method of austenitic stainless steel strip. CONSTITUTION:By dipping the steel strip into pickling acid liquid containing 50-400g/l hydrofluoric acid, 50-400g/l nitric acid and 0.5-50g/l hydrochloric acid and, as necessary, one or two kinds of noble metal ions of Pt, Pd, etc., or by spraying the pickling acid liquid to the steel strip, both of high speed dissolving and the secureness of good surface characteristic of the austenitic stainless steel are attained. By applying this technique, the improvement of the descaling capacity of the austenitic stainless steel without damaging the surface characteristic of the acid cleaned strip is achieved. Further, by controlling the hydrochloric acid concn., the dissolving capacity can be controlled according to the level from the hot-rolled strip with good surface characteristic to that having scabs, etc.