Laboratory methods were developed for correlating electrochemical deterioration rates of various graphite and high- silicon iron anodes with current drain in NaCl electrolytes of 50, 1000 and 5000 ohm-centimeter specific resistivities. The test apparatus and procedure are described and data obtained are presented. The influences of specific resistivity of the electrolyte and of anodic current density on the electrochemical deterioration rates were investigated. Deterioration of graphite increases with increasing specific resistivity or decreasing NaCl concentration of the electrolyte. The effect of impregnation of graphite anodes on the electrochemical deterioration rates and the variation of this effect with electrolyte specific resistivity are indicated. Additional investigations in 16.3 ohm-centimeter NaCl electrolyte have been added to permit closer correlation with sea water conditions. Data on high-silicon iron anodes in high-resistivity electrolytes indicate lower deterioration rates than achieved with graphite anodes and such applications are recommended for consideration. In low-resistivity solutions, chemical attack of high-silicon iron by chlorine generated and trapped at the anode surface can be appreciable and should be considered in anode designs and applications. 5.2.3
Electrochemical Deterioration of Graphite And High-Silicon Iron Anodes In Sodium Chloride Electrolytes⋆ Available to Purchase
SIDNEY TUDOR is supervisory chemist (physical) in charge of the Electrochemistry Unit at the Material Laboratory, New York Naval Shipyard, Brooklyn. His experience includes research in cathodic protection, electrolytic derusting, polarography and electrochemical surface reactions. He has a BA from Brooklyn College and an MS in chemistry from New York University. He is a member of NACE.
WALTER L. MILLER—Head of the Metal Chemistry Section, Material Laboratory, New York Naval Shipyard, Brooklyn, he entered government service in 1930 and has been occupied in problems associated with the chemistry of metals since 1934. He has a BA in chemistry from Columbia (1929) and has had additional courses at Pratt Institute and Brooklyn Polytechnic Institute. Among other technical organizations he is a member of NACE.
ARTHUR TICKER is a chemist in the Material Laboratory, New York Naval Shipyard, Brooklyn. For the past three years has been occupied with research and development of cathodic protection systems as applied to the hulls of naval vessels. He previously worked in the fields of metal chemistry and protective coatings. He has a BS in chemistry, Long Island University (1941) and is a member of NACE and ACS.
HERMAN S. PREISER is a corrosion engineer for the Bureau of Ships, U. S. Navy Department, Washington, D. C. For the past five years he has been engaged as the project engineer in the research and development of marine cathodic protection systems and associated studies. He has written many articles in his field and holds a patent on a new type bilge keel anode. Mr. Preiser is a professional engineer in the District of Columbia, and in Virginia.
