油温对海底输油管线阴极保护的影响

目的研究油温对海底输油管道阴极保护的影响。方法通过模拟海水实验,参照GB/T17848—1999实验方法,分析铁电极、铝电极和偶合电极在不同油温下的腐蚀电位和偶合电流的变化规律,测试25℃和75℃海水中牺牲阳极的工作电位,并计算阳极的电流效率,观察阳极的腐蚀形貌。结果在25~75℃范围内,铝电极随着温度升高自腐蚀电位负正移,铁电极随着温度升高自腐蚀电位负移。偶合电位正移,偶合电流显著增大。结论与25℃相比,牺牲阳极在75℃海水中,保护电位下降,阴极保护效果降低。

Effect of Oil Temperature on the Cathodic Protection of Submarine Oil Pipeline

ABSTRACT:Objective To study the effects of the oil temperature on cathodic protection devices of submarine oil pipeline. Methods Referring to the testing standard GB/T 17848—1999, the changing rules of corrosion potential and coupled current of the iron electrode, aluminum electrode and coupling electrode at different oil temperatures were analyzed through simulated seawater experiment. The working potentials of sacrificial anode at 25 ° and 75 ° were tested, and the current efficiency of anode was cal-culated. The corrosion morphology of anode was observed. Results In the range of 25 ° to 75 ° , the corrosion potential of alumi-num electrode increased, the corrosion potential of iron electrode decreased, the coupled potential shifted to positive value and the coupled current significantly increased with increasing temperature. Conclusion The protection potential and protection current effi-ciency of sacrificial anode decreased in 75 ° seawater when compared to those at 25 ° .