caa a22 4500 475815513 CHVBK 20180406123809.0 cr unu---uuuuu 170329e20000301xx s 000 0 eng 10.1023/A:1003903806668 doi (NATIONALLICENCE)springer-10.1023/A:1003903806668 Anodic polarization behaviour of cast iron alloys in deaerated concentrated H3PO4 solutions containing Cl− and F− ions [Elektronische Daten] [M.S. Abdel-Aal, A.A. Hermas] The anodic behaviour of four cast iron alloys containing up to 16.7% Ni, in deaerated 60 wt% H3PO4 with and without 5 × 10−3 M F−, Cl− ions and 1:1 Cl−/F− mixture was studied by the potentiostatic technique. Values of E corr of the alloys are markedly influenced by their composition. The anodic behaviour in the active region is controlled by Fe in the alloys and the dissolution reaction is characterized by Tafel slopes, b a, between 64 and 88 mV (decade)−1. A two-electron transfer mechanism for the anodic dissolution is proposed. Passivation of the alloys is due to the formation of oxide layers including Fe2O3 and/or Fe3O4. Both critical and passive c.d. (I cc and I P) are markedly increased in the presence of Cl− ions, but the presence of F− ions inhibit the active dissolution of the alloys. The Tafel slope for oxygen evolution reaction (o.e.r.) in the transpassive region, $$b_{{\text{O}}_{\text{2}} } $$ is 240 ± 25 mV. In the proposed mechanism for the o.e.r., the rate determining step is an electron transfer reaction and possible interpretation of the high Tafel slopes is given based on the dual barrier model. Kluwer Academic Publishers, 2000 anodic behaviour nationallicence cast iron alloys nationallicence chloride ion nationallicence chromium nationallicence fluoride ion nationallicence nickel nationallicence phosphoric acid nationallicence Abdel-Aal M.S. Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt aut Hermas A.A. Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt aut Journal of Applied Electrochemistry Kluwer Academic Publishers 30/3(2000-03-01), 339-345 0021-891X 30:3<339 2000 30 10800 https://doi.org/10.1023/A:1003903806668 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1003903806668 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Abdel-Aal M.S. Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 700 1- Hermas A.A. Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 773 0- Journal of Applied Electrochemistry Kluwer Academic Publishers 30/3(2000-03-01), 339-345 0021-891X 30:3<339 2000 30 10800 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer