ARTÍCULO
Effect of ascorbic acid on hydrogen peroxide decomposition into an environmentally friendly mixture for pickling of 316L stainless steel.
Narváez Hernández, L.
Miranda Vidales, J. M. and
MartÃnez-Flores, E. E.
Protection of Metals and Physical Chemistry of Surfaces, 50(3), 384-390.
DOI: 10.1134/S2070205114030058, 2014.
ABSTRACT:
One of main disadvantages of using environmentally friendly chemical mixtures for pickling, is stabilization of hydrogen peroxide (H2O2), due to its decomposition is affected by the presence of metal ions. In previous studies, ptoluenesulfonic acid (C7H10O4S) was used as a hydrogen peroxide stabilizer; however, benzene rings in its structure have a certain level of toxicity. In this work, ascorbic acid (C6H8O6) was tested as a stabilizer agent for H2O2 in a pickling mixture composed by sulfuric acid (H2SO4) and hydrofluoric acid (HF)–H2O2, this mixture was tested on 316L stainless steel (SS). Decomposition of H2O2 in pickling solu tion was evaluated for different ferric ions concentration between 0 to 40 g/L and at different temperatures from 25° to 60°C. Pickling rates at 25°C for 316L SS were 26873 mg/dm2 and 27799 mg/dm2 using ascorbic acid and ptoluenesulfonic acid, respectively. Ascorbic acid has a positive influence on stabilization processes of H2O2.