Effect of Reaction Temperature on Pickling of 430 Stainless Steel
stainless steel is used as raw material and pickling in HCl-based electrolytes is adopted, and the effect of pickling temperature on removal behavior of the oxide layer on stainless steel is systematically studied, study found that the oxide layer of stainless steel after heat treatment in the lab is composed of Fe2O3 and Cr2O3, at different temperatures, with the increasing of duration, corrosion potential of stainless steel after heat treatment shows fall followed by rise, and corrosion potential of stainless steel in 60°C is obvious higher than in 50 °C; with temperature increasing, the weight loss of stainless steel after pickling increase with large range, and the weight loss of the oxide layer of stainless steel increases as the duration increases.
Hydrogen Peroxide Decomposition in an Environmentally Friendly Pickling Solution for AISI 316L Stainless Steel, January 2005
Abstract There is increasing interest in the utilization of ecological bath solutions for the pickling of stainless steel (SS), because conventional nitric (HNO3) and hydrofluoric (HF) acid mixtures generate high NOx emissions. A mixture of hydrogen peroxide (H2O2), sulfuric acid (H2SO4), and HF has been tested in this study as an environmentally friendly pickling solution for AISI 316L SS (UNS S31603). The decomposition of H2O2 and the H2SO4-HF-H2O2 mixture was assessed at different temperatures from 25°C to 60°C, 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 H2O2. The AISI 316LSS pickling rate found at 50°C was 2.35 × 103 mg/dm2-day (mdd) and 0.12 × 103 mdd, respectively, in the absence and presence of 40 g/L ferric ion.
Tenue mecanique de couches d'oxyde thermique generees sur le chrome et sur quelques aciers inoxydables ferritiques : etude des contraintes et de l'adherence
Les couches d'oxyde thermique, a l'origine de la resistance a l'oxydation a haute temperature de nombreux materiaux, doivent rester continues et adherentes au substrat pour assurer sa protection en service. Le present travail vise a comprendre quels parametres influent de facon determinante sur la tenue mecanique de ces couches. Il porte sur les oxydes riches en chrome formes sur des aciers inoxydables ferritiques. Le comportement de l'oxyde de chrome cr 2o 3 forme sur le chrome pur est egalement analyse en tant que systeme modele. La tenue mecanique des films d'oxyde est analysee d'une part en terme de contraintes, qui peuvent endommager le film d'oxyde, et d'autre part en terme d'adherence du film sur son substrat. Ce travail presente tout d'abord les contraintes generees dans la couche d'oxyde au cours de sa croissance a haute temperature et lors du refroidissement du systeme. Les contraintes sont determinees par spectrometrie raman. L'adherence de l'oxyde sur son substrat est ensuite analysee. Un test de gonflement-decollement a ete developpe specifiquement afin de mesurer l'energie d'adherence oxyde-substrat. Le role des conditions d'oxydation, en particulier la nature de l'atmosphere oxydante, et des elements d'addition est mis en evidence et discute a la lumiere des observations experimentales.