The Pitting Potential of Stainless Steels in Chloride Media

Abstract

Anodic and cathodic potentiostatic polarization curves were obtained for various stainless steel alloys in sodium chloride and calcium chloride solutions. In the pH range 2 to 8 pitting occurs in the passive region. For a given chloride ion concentration pit initiation does not occur until a certain electrode potential, the pitting potential, is reached. The pitting potential is dependent on alloy composition and may be used as a relative measure of pitting tendency for various alloys. Calcium ion enobles the pitting potential when the chloride ion concentration is about 1N or less. The implications of a pitting potential on passivity theories is briefly discussed.

Effect of Sn on the Pitting Corrosion Behavior of Ultra‐Purified 17% Cr Ferritic Stainless Steel

“…If the active sites are immobilized, the dissolution of steels can be greatly inhibited. On the other hand, since the cathodic reaction is the oxygen reduction, which is controlled by diffusion rate of limited dissolved oxygen for the low oxygen solubility, it can also be inferred that the activity of the surface for the cathodic oxygen reduction may not be increased. Inhibition of the anodic reaction may not, therefore, be counteracted by activation of the cathodic reaction.…”

Decorative Electrodeposited Metallic Coatings

“…Most brighteners contain sulphur, which becomes incorporated in the deposit; this is the reason why brightnickel deposits are less noble than Watts or semi-bright deposits. 19 Various authors have investigated the effects of organic addition agents on properties. 2o - 22 The ideal properties demanded of bright-nickel deposits and of the baths used to obtain them were summarized by Eckelmann 23 as early as 1934 and reiterated by Saltonstall 24 twenty years later.…”

Studies on the Pitting Corrosion of the Delta‐52 Steel in aqueous solutions. 2. Variation of the pitting potential in relation to the concentration of the aggressive anion

“…have been usefully applied to the study of pitting corrosion (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). In presence of anions enabling pitting corrosion, the potential does not reach oxygen evolution, and the current increases steadily at lower potential, dependent on a number of factors (6)(7)(8)(9)(10)(11)(12)(13).…”

“…In presence of anions enabling pitting corrosion, the potential does not reach oxygen evolution, and the current increases steadily at lower potential, dependent on a number of factors (6)(7)(8)(9)(10)(11)(12)(13). This increase in current does not occur directly after the addition of the aggressive ion, but a certain time elapses.…”