用镁牺牲阳极防三相分离器内壁腐蚀的研究

Application of Sacrificing Magnesium Anode in Corrosion Protection of Inner Wall of Triphase Separator Used in Natural Gas Field

针对大庆天然气公司某大队实际工矿条件下的压力容器内壁腐蚀问题,用柴油、乙二醇和水配制成模拟的混合相体系,借助静态、动态法进行了腐蚀试验,利用极化曲线法测定了体系的开路电压、腐蚀电位、腐蚀电流密度、腐蚀速率、最小保护电位和最小保护电流密度。结果16MnR钢片的开路电位为-610.0mV,腐蚀电位为-631.0mV,腐蚀电流密度为7.680μA/cm2;镁阳极开路电压为-1.507V,腐蚀电位为-1.470V,腐蚀电流密度为11.200μA/cm2。确定最小保护电位为-0.981V,最小保护电流密度为110.700μA/cm2,镁阳极的实际保护电位为-1.200V左右。结果证明,采用牺牲阳极法可以对该容器内壁实现保护作用。

With a view to the corrosion of the inner walls of the com-pressive vessels used in natural gas field, static and dynamic corrosion tests were conducted using a mixed fluid of diesel oil, gly-col, and water as the simulating corrosive medium. The open -voltage, corrosive potential, corrosive current density, corrosive rate, lowest protective potential, and lowest protective current density were measured using polarized curve method. The results indicated that the 16MnR steel slice had an open potential of -610.0 mV, corrosion potential of -631.0 mV, and corrosion current density of 7. 680 μA/cm2, while the magnesium anode had an open potential of - 1. 507 V, corrosion potential of - . 470 V , and corrosion current density of 11. 200 μA/cm2. At the same time, the lowest protective potential and lowest density protective current density were measured to be - 0. 981 V and 1 10. 700μA/cm , respectively, while the actual protective potential was determined to be - 1.200 V. Therefore, the titled triphase separator could be well protected from inner - wall corrosion at the natural gas field using the sacrificing Mg anode.