Considerable expenditure is required to combat corrosion of steel hydraulic structures and equipment in rivers. Until recently, the chief method of suppressing such corrosion was the use of resistant enamels or paints. Owing to the considerable weights of equipment in hydroelectric power stations and the difficulties of dismantling, transportation and reassembly, any solution which will eliminate anticorrosive treatment of large items ofplantsmust be attractive. Extensive research has therefore been made into the possibility of electrochemically protecting submerged metal structures so as to dispense with time-consuming painting work. This method should be very popular for protecting steel components in hydraulic engineering structures.Construction engineers will be interested in techniques involving corrosion-resistant structural materials, especially aluminum alloys, with the aim of prolonging service life. Their high specific strengths and resistances enable such alloys to protect structures from corrosion and greatly reduce their weights; assembly is easier and hoisting facilities need not be so extensive. The present paper gives the results of a program of research at the Gipromorneft' Institute (Baku), aimed at correlating the mechanical and corrosion properties of aluminum alloys under conditions imposed by the average flow of the Volga at the V.

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Reviewed by M. S. Trffel', During recent years, a large volume of work has been undertaken at several Soviet hydroelectric plants--the V. I. Lenin and the Twenty-Third CPSU Congress plants on the Volga, the V. I. Lenin Mingechaursk plant, the V. I. Lenin Plyavin'sk plant, the Kamsk plant, the Gor'kovsk plant, the Great October 50th Anniversary Bratsk plant, the Kakhovsk plant, and the V. I. Lenin Dneprog4s plant, as well as the Kislogubsk peak-load electric power plant --relating to the electrochemical protection of the mechanical equipment, metal structures, and hydropower equipment of those plants. The experience gained has demonstrated not only the technical feasibility of the application of electrochemicaI protection infresh-waterrivers, but also its high effectiveness. This fact has indicated the convenience of issuing a special document regulating the application of this type of protection.Taking into consideration the characteristics of the equipment to be protected at the hydroelectric plants (laNe dimensions, possibility of being hit by floating ice and other bodies, proximity to concrete masses, and high specific resistance of the water), it was necessary to establish the conditions governing the reliability of such equipment, and the corresponding constructional solutions of their components. The preparation of the document was entrusted to the Gidromorneft' Institute and the V. I. Lenin Hydroelectric Plant. The Gidromontazh Trust, the Institute of Physical Chemistry of the Academy of Sciences of the USSR, the ORG~S, and other organizations participated in that task. The instructions were issued by the Committee on Corrosion and Metal Protection of the Azerbaidzhan Council of the NTO of Power and Electrical Engineering Industries.In view of the possibility of substantial differences in the corrosion properties of the water from different rivers, the instructions regulate all the operations relating to the protection work, beginning with the engineering field inspection and ending with the methods of adjusting and operating the protection facilities. In the preparation of the instructions, the interests of all the departments which operate hydraulic structures on river waters (power, irrigation, waterways, etc.) were taken into consideration.The first section of the instructions deals with the investigation relating to the behavior of metaIs in river waters, the determination of rates of corrosion, the parameters of electrochemical protection, and the evaluation of the effectiveness of cathodic protection. A particular feature of the investigation methods proposed are the schemes which permit preventing the effect of the high specific resistance of the water on the results of the evaluation of the protection parameters, by compensating the resistance of the medium present between the metal and the compensating electrode. This approach, which is not applicable to the evaluation of the action of electrochemical protection in conductive seawater, is extremely important for reaching correct conclusions conc...

During the past 5-6 years, at the hydroelectric plants of the Ministry of Power and Electrification of the USSIL a large volume of work has been carried out concerning the industrial testing and determination of the effectiveness of present-day methods for the protection against corrosion of metal structures, mechauical equipment, and turbines of hydroelectric plants; this experience permits choosing highly improved methods of carrying out such protection. The organizations possessing practical experience in this field have formulated recommendations and have issued, for general use, guiding instructions for the application of the most effective of those methods --electrochemical protection. * * Taking into consideration the necessity of giving training to the personnel of hydroelectric plants on the specific methods of planning, introducing, and implementing electrochemical protection of the equipment and metal structures of hydroelectric plants, the Kuibyshev Regional Council of the NTO, jointly with the Azerbaidzhan Council of the NTO of Power and Electrical Engineering Industries, organized, from July 7 to luly 17, 1969, a special seminar at the V. I. Lenin Volga Hydroelectric Plant, which was attended by representatives from the Ministry of Power and Electrification of the USSR (Min4nergo), and by operating personnel from 18 large hydroelectric plants in the Soviet Union.A systematic cycle of lectures was presented at the Seminar, dealing with the corrosion and protection of metal structures of hydroelectric plants, by applying modern varnish and metal paints, inhibitors, lubricants, and electrochemical protection. The participants became acquainted with the application of cathodic protection and coatings on the hydrometal structures and the hydromechanical equipment of the V. I. Lenin Volga hydroelectric plant, which are fully protected against corrosion by means of cathodic installations. They became acquainted also with the methods developed for operating them.During the final part of the seminar, the participants exchanged experience on protection against corrosion at different Soviet electric plants. The seminar adopted recommendations proposing the wide introduction of electrochemical protection of hydromechanical equipment and metal structures at hydroelectric plants.

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