There is increasing interest in the utilization of ecological bath solutions for the pickling of stainless steel (SS), because conventional nitric (HNO{sub}3) and hydrofluoric (HF) acid mixtures generate high NO{sub}x emissions. A mixture of hydrogen peroxide (H{sub}2O{sub}2), sulfuric acid (H{sub}2SO{sub}4), and HF has been tested in this study as an environmentally friendly pickling solution for AISI 316L SS (UNS S31603). The decomposition of H{sub}2O{sub}2 and the H{sub}2SO{sub}4-HF-H{sub}2O{sub}2 mixture was assessed at different temperatures from 25℃ to 60℃, with ferric ion contents from 0 to 40 g/L, with and without stirring of the aqueous acid mixture. The p-Toluene sulfonic, 3-hydroxybenzoic, and 4-dodecylbenzene sulfonic acids were tested as stabilizers for H{sub}2O{sub}2. The AISI 316LSS pickling rate found at 50℃ was 2.35 × 10{sup}3 mg/dm{sup}2-day (mdd) and 0.12 × 10{sup}3 mdd, respectively, in the absence and presence of 40 g/L ferric ion.
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