常压石油储罐腐蚀及防护

介绍处于干旱西北地区的石油储罐在没有设置电化学保护措施下,长期在酸、碱、盐及土壤、雨水、积雪自然环境中遭受腐蚀,致使储罐处于不安全在役状态,其中,油罐外壁和顶部受到大气腐蚀,罐底主要受到土壤腐蚀,罐壁第一块圈板金属被沥青砂散水坡掩埋处的酸性雨水腐蚀。油罐内壁的腐蚀根据内壁所处的不同环境,出现4个腐蚀区。罐顶部腐蚀的主要原因都是水蒸汽、空气中的氧以及油品中挥发的硫化氢造成的电化学腐蚀。腐蚀包括溶解氧、电化学腐蚀、二氧化碳、硫化氢等,从罐体选材、施工、维护、保养,有针对性的防护及合适的防护措施,可以有效地避免事故发生。

Corrosion of Atmospheric Oil Tanks and Protection

The corrosion of oil storage tanks in long-term acidic,caustic,salt,soil,water and snow environments and unsafe on-service operations of oil storage tanks without electro-chemical protection in the dry China northwest region is described.The external wall and head section of the tanks are subject to atmospheric corrosion,the tank bottom is corroded by soil and the first ring plate of tank wall is corroded by acidic rain water.4 corrosion areas are found in the internal wall of tank because of different service environments of internal tank wall.The corrosion of tank head is mainly the electro-chemical corrosion caused by steam,oxygen in air and volatilized hydrogen sulfide in the oil.The corrosions are dissolved oxygen corrosion,electrochemical corrosion,CO2 corrosion and H2S corrosion.The taking of appropriate protection measures in respect of material selection,construction and maintenance can effectively prevent the relative corrosion accidents from occurring.