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.
Adhesion of thermal oxide scales grown on ferritic stainless steels measured using the inverted blister test
Abstract The inverted blister test was used to study the adhesion of chromium-rich oxide scales thermally grown on several ferritic stainless steels. With this technique, a quantitative determination of the adhesion energy of the oxide on its substrate was possible. The adhesion energy is found to vary between 3 and 170 J m −2 depending on the specimens. It appears that the parameters influencing adhesion are oxide thickness and the nature of the minor alloying elements present in the alloy. The microstructural observation of both sides of the oxide/alloy interface after debonding provides important information on adhesion and spallation.
Anodic pickling of stainless steels in sulphuric acid
Potentiostatic pickling in 20% aqueous H2SO4 was investigated on hot- and cold-rolled strips of stainless steels from industrial lines, in order to assess the potentiality of this technique. Experimental evidences for AISI Types 202, 304, 316, 410 and 430 are given. Optimum pickling conditions were defined on the basis of the potentiodynamic behaviour of oxidized specimens.Visual and electrochemical evaluation of pickled surfaces showed that:(i)The potentiostatic technique makes descaling and pickling of stainless steels quite feasible in sulphuric baths;(ii)remarkable advantages result over ordinary chemical treatments in terms of speed of scale removal;(iii)a higher efficiency of restoration of passivity properties also results.