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| POTENTIAL DISTRIBUTION ON CATHODICALLY PROTECTED INTERNAL SURFACE OF PIPE |
| Xu Naixin Zhang Chengdian Zhou Fengming and Ding Cuihong (Shanghai Institute of Metallurgy. Academia Sinica) |
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Abstract Cathodic protection is generally recommended to control the external corrosion of pipe. Sometimes, however, internal cathodic protection is required. The impressed current protection is usually provided by using discrete inert anodes placed at intervals along the pipe. The characteristics of potential distribution under this condition is perhaps the most importan, aspect because of the limited space inside pipe. Corresponding mathematical expressions were derived. The potential is evaluated as a hyperbolic function of the distance from anode. The relationship has been verified experimentally. The dependence of potential on electrolyte resistivity, polarization resistance of inner surface, pipe diameter and length of pipe is illustrated. The protection current demand was also evaIuated on the basis of non-unlform distribution. Both laboratory investigation and operation experience showed the time-dependence of potential, which could be ascribed to the increase of polarization resistance of the pipe surface. The theoretical consideration presented here would be useful for the design of internal cathodic protection system of pipe in general and for the selection of the inter-anode spaceing in particular.
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Received: 25 August 1987
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[1] Morgan, J. H., Corrosion, 15(8) , 417 (1959)
[2] 星野九平,防食技术,10(5) ,193(1961)
[3] 佐藤史郎,山内重德,防食技术,25(10) ,611(1976)
[4] 中国科学院上海冶金研究所,管道内壁阴极保护时的电位分布和表面极化电阻,全国阴极保护技术学术交流会资料(1978)
[5] 叶明库、林华水、田昭武,材料保护,4,11(1982)
[6] 中国科学院金属腐蚀与防护课题协作组,腐蚀与防护,2,41(1982)
[7] 上海石油化工总厂技术资料第一辑,化工腐蚀与防护(1981)
[8] McGrath. J. N.; Tighe-Ford, D. J., Corrosion, 40(11) , 604 (1984) |
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