Anodes for Cathodic Protection

Fig. 1-13 The first deep anode for cathodic protection in Germany.

Imoi, H., Saito, Y., Kobayashi, M. and Fujiyama, S., Pitting-corrosion-resistant Chromium Stainless Steel , Japan Kokai 7300, 221 (1973) C.A., 79, 22569a Sato, E., Tamura, T. and Okabe, T., Aluminium Anode for Cathodic Protection. 7 Pitting and Corrosion Potentials for Gallium in Sodium Chloride Solutions , Kinzoku Hyomen Gijutsu, 24, 82 (1973) C.A., T9, 12792d... 

Morgan, J. FI. Lead Alloy Anode for Cathodic Protection , Corr. Tech. 10/12. 348-352 (1958)... 

This chapter is intended as an introduction and guide to the use of sacrificial anodes for cathodic protection. 

It has now gained acceptance as an impressed current anode for cathodic protection and has been in use for this purpose since 1971. The anode consists of a thin film of valve and precious metal oxides baked onto a titanium substrate and when first developed was given the proprietary name dimensionally stable anode , sometimes shortened to DSA. Developments on the composition of the oxide film have taken place since Beer s patent, and this type of anode is now marketed under a number of different trade names. 

Pb alloys have been investigated to determine their suitability as anodes for cathodic protection. Crennel and Wheeler carried out tests on Pb-Ag alloys and found that Pb-lAg was suitable for use in seawater providing that the current density did not exceed 100-200 Am since at high current... 

DcMilIc Campbell, E., High Silicon Iron Anodes for Cathodic Protection , Corrosion, 27 No. 4, 141 (1971)... 

The chemical reactivity of metallic Mg has been utilized in several ways. It is employed in the reduction step in the manufacture of Ti, in the deoxidation and desulfurization of steels and in the nodularization of cast iron. It has also been used for the preparation of photoengraving plates, in dry batteries, and as a sacrificial anode for cathodic protection of other metals. 

Development of Impressed Current Anodes for Cathodic Protection... 

Other metals that have favorable reversible Flade potentials and form passive film on their surfaces include titanium, silicon, aluminum, tantalum, and niobium. Naturally formed aluminum oxide protects the underlying aluminum metal at pH between 4 and 8. Titanium possesses very high oxidizing potentials and is used to manufacture anodes for cathodic protection systems for the chlorine-alkafi process (production of hydrogen, chlorine, and sodium hydroxide) and many other appfications. 

The high-alloy silicon irons are used in draining pipelines, pumps, valves, other process equipment, and anodes for cathodic protection with impressed current. 

Sprayed concrete, shotcrete (dry sprayed) or gunite (wet sprayed) are methods of rapidly applying concrete to soffits or vertical surfaces. It can be used over patches and to overlay metal mesh anodes for cathodic protection as described in Section 7.6. It is sometimes applied as a temporary cosmetic repair in the Northern USA and Canada when concrete has spalled or is in danger of spalling. As it does nothing to slow the corrosion rate it is comparable in effectiveness to patch repairing, and may suffer from the same incipient anode problem. 

Bagnulo, L. (1973). Adhesive sacrificial anode for cathodic protection. British Patent 1,474,413, April 19 (May 25, 1977), 5 pp. 

Fukutani, E., and Akiba, T. (1961). The relation between corrosion of propeller shaft and zinc anode for cathodic protection of propeller. Corros. Eng., 10, 289-292. 

Knuckley, P. J., and Dempster. N. S. (I%3). Development of zinc alloy anodes for cathodic protection of marine structures. Australasian Corros. Eng., 7, 15-22. 

Paul, N. (1981). Zinc anode versus aluminum anode for cathodic protection. Lead,... 

Souske, R. (1959). (Use of zinc anodes for cathodic protection.) Corros. Anticorros. 

Anderson, E.P. (1961) Method for preparing anodes for cathodic protection systems. US Patent 2,998,359 August 29,1961. 

C-casting, W-wrought products, A-anodes for cathodic protection. 

The research on corrosion, started in this institute in the 1950s, continued successfully further. The intergranular corrosion of steels was measured by an electrochemical potentiodynamic reactivation method [310-312]. Since the 1960s, the passivity of brass was further studied, the rates of corrosion were measured by polarization resistance, the effect of deformation on anodic dissolution of steels was followed, and the surface roughness of metals was measured other subjects of research were, e.g., the behavior of passive films on steel, the effect of compositirai and motion of electrolyte on corrosion of passivated aluminum, the cathodic protection of passive metals against corrosion, the anodes for cathodic protection of steels, etc.[313-316]. Measurements of polarization resistance in the system iron—concentrated sulfuric acid or boiling nitric acid, of corrosion and matter... 

Magnesium alone and its alloys have been employed intensively as sacrificial anode for cathodic protection and are now considered for numerous present and future promoting applications (see Section 2.4). 

Yu BL, Uan JY, (2006), Sacrificial Mg film anode for cathodic protection of die cast Mg-9 wt.%Al-l wt.%Zn alloy in NaCl aqueous solution , Scripta Materialia, 54, 1253-1257. 

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