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It is possible to determine the pitting corrosion resistance of a stainless steel in a given solution of a chemical process by electrochemical techniques. However, it is known that the result is influenced by the test parameters. The aim of this study was to determine the influence of the main test parameters, scan rate, imax; agitation/flow rate, and surface pretreatment on the electrochemical response of 316Ti/1.4571 stainless steel in an acidic (250 ppm Cl−, pH: 4, T: 30 °C) and an alkaline (4% Cl−, pH: 9, T: 80 °C) solution. The results were compared with classical immersion test results. The main result was that the agitation/flow rate had the greatest impact, with stagnant conditions giving very conservative results, followed by imax, which had an influence on the repassivation potential. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of phosphate species on Ag(111) and Ag(100) single crystal surfaces was studied by experimental techniques and theoretical calculations. Characteristic cathodic/anodic potential peaks (V p ) appear in the current density-potential curves ( j – V ) for H 2 PO 4 − , H 3 PO 4 , and in the case of PO 4 3 − for concentrations lower than 0.1 M, where the interaction is stronger for the Ag(100) electrode. This demonstrate that the adsorption is sensitive to the surface structure. The adsorption energy (E ads ) of the different species on both surfaces was studied by means of DFT-vdW calculations. All phosphate species have tri-dentate binding. The |E ads | increased for the H 3 PO 4 ; H 2 PO 4 − ; HPO 4 2 − and PO 4 3 − sequence, and the tetrahedral structures are compressed. Although the same trend was observed on both crystalline surfaces, the films have the symmetry of the substrate, C 3 v and C 4 v . The influence of hydroxide co-adsorption was studied for different [HPO 4 2 − ]/[PO 4 3 − ] ratios in solution. The strength of adsorption obtained from experimental and theoretical calculations show an excellent qualitative correlation. [ABSTRACT FROM AUTHOR]