Reference

Effects of some new inhibitors and pH on dissolution characteristics of iron

Effects of some new inhibitors and pH on dissolution characteristics of iron. Erbil, Mehmet (Fen-Edebiyat Fak., C.U., Adana, Turk.). Doga Bilim Derg., Seri A1, 8(3), 250-6 (Turkish) 1984. CODEN: DBAMEE. DOCUMENT TYPE: Journal CA Section: 72 (Electrochemistry) Section cross-reference(s): 55 Inhibition effects of 1,4-phenylenebisphosphonic acid [880-68-2], 1,3-propanediylbisphosphonic acid [4671-82-3], and 1,6-hexanediylbisphosphonic acid [4721-22-6] were studied by observing the changes of the dissoln. characteristics of pure Fe for various inhibitor concns. and pH. For this purpose, anodic current-potential curves were obtained by using a potentiokinetic method in solns. of 0.5M Na2SO4 with and without the inhibitors in a H atm. A comparison of the curves showed that all of them are surface-active inhibitors.

Inhibition of pitting corrosion of iron and steel in neutral solutions by organic phosphonic acid derivatives

Inhibition of pitting corrosion of iron and steel in neutral solutions by organic phosphonic acid derivatives. Paatsch, W. (Bundesanst. Materialpruef., Berlin D-1000/45, Fed. Rep. Ger.). Werkst. Korros., 35(5), 179-85 (German) 1984. CODEN: WSKRAT. ISSN: 0043-2822. DOCUMENT TYPE: Journal CA Section: 55 (Ferrous Metals and Alloys) Pitting corrosion and inhibition by org. phosphonic acid derivs. were investigated for pure Fe, mild steel, 99.5% Ni, and annealed austenitic steel (AISI 304 [11109-50-5]) electrodes in aerated, hot stirred, and Cl- contg. borate buffer soln. of pH 8.0. Best results were obtained for Ni. The inhibition efficiency decreases in the order benzene-1,4-diphosphonic acid [880-68-2], hexane-1,6-diphosphonic acid monohydrate [4721-22-6], propane-1,3-diphosphonic acid monohydrate [4671-82-3], amino-tris(methylene-phosphonic acid) [6419-19-8], and 1-hydroxyethane-1,1-diphosphonic acid monohydrate [2809-21-4]. For Fe and mild steel, the last 2 substances do not show any inhibition efficiency. For stainless steel none of the compds. investigated can be used as inhibitor for pitting corrosion. For all materials, inhibition depends on the ratio of the inhibitor to the Cl- concn. Potentiodynamic measurements as well as cathodic discharging expts. of passive electrodes show that the inhibiting mols. are not incorporated into the passive layers but work by the adsorption mechanism. Results of photopotential and AES investigations are in agreement, with this statement.