3.5%NaCl溶液中电缆铝护套的交流腐蚀特性

AC Corrosion Characteristics of Cable Aluminum Sheath in 3.5%NaCl Solution

近年来,沿海地区陆续发现电缆铝护套腐蚀现象,为了研究电缆铝护套在交流电作用下的腐蚀过程,在3.5%NaCl溶液中测定了外护套破损时,不同交流电流流过时铝护套的穿孔时间,同时记录了铝护套表面腐蚀形貌的变化。结果表明:电缆铝护套穿孔时间与铝护套表面流出的电流成反比。腐蚀速率与铝护套表面流出的电流密度成正比;腐蚀初期呈现点蚀形貌,靠近圆孔中心位置点蚀坑更加密集,随着时间的延长,腐蚀严重区域向边缘扩散。

In recent years,corrosion of the aluminum sheath of cables had been discovered in coastal areas.In order to study the corrosion process of the cable aluminum sheath under the action of alternating current,the perforation time of the aluminum sheath was measured when the outer sheath was damaged in 3.5%NaCl solution,and the change of the surface corrosion morphology of the aluminum sheath was recorded at the same time when different alternating currents passed.The results showed that the perforation time of the aluminum sheath of the cable was inversely proportional to the current flowing out of the surface of the aluminum sheath.The corrosion rate was proportional to the current density flowing out of the surface of the aluminum sheath;pitting morphology appeared in the early stage of corrosion,and the pits were more dense near the center of the hole.As time went by,severely corroded area spread to the edge.