ELECTROCHEMICAL BEHAVIOUR OF Al-BRASS IN SEAWATER
Corrosion of the Al-brass in 3.5 % NaCl solution and natural seawater was investigated with potentiodynamic polarization technique. Corrosion rate obtained in natural seawater was higher than in 3.56 % NaCl solution. The metallographic examinations indicated the occurrence of pitting corrosion in both cases.
Impingement Corrosion of Condenser Tubes
AbstractThe problems of impingement corrosion of condenser tube materials are reviewed, with special reference to the power industry of the UK. The South Eastern Region of the Central Electricity Generating Board has set up a laboratory to study the corrosion behaviour inflowing sea water of metals used in power station cooling water systems. The jet impingement facilities of the laboratory are described and the results of recent work presented. These include the impingement characteristics of some standard condenser tube materials, the modification of these characteristics by such methods as cathodic protection and ferrous sulphate dosing of the sea water, and the resistance to impingement corrosion of some new materials. Particular attention is paid to titanium and its resistance to this form of corrosion.
The nature of protective films formed on a CuFe alloy
Abstract A Cu alloy (CDA 194) containing α-Fe particles in a Cu matrix develops protective corrosion product films in chloride solutions after an initial period of relatively rapid attack. The protective film is a mixture of Cu2O and lepidocrocite. The lepidocrocite produces significant polarization of the cathodic reduction of dissolved oxygen which accounts for its protective action. It is formed in the corrosion product film by galvanic corrosion of the Fe particles to ferrous ions, oxidation of the ferrous ions by dissolved oxygen and electrophoretic deposition of a positively charged Fe(OH)3 colloid on the cathodic Cu matrix.