动态海水中保护电位对钙质沉积层形成的影响  

The Influences of Protection Potentials on the Formation of Calcareous Deposits in Dynamic Seawater

作　　者：李成杰[1] 杜敏[1] 李妍[2] 张国庆[2] 张艳芳[2] 

机构地区：[1]中国海洋大学化学化工学院,海洋化学理论与工程技术教育部重点实验室,山东青岛266100 [2]海洋石油工程股份有限公司设计公司,天津300451

出　　处：《中国海洋大学学报（自然科学版）》2011年第7期149-153,共5页Periodical of Ocean University of China

基　　金：国家科技重大专项(2008ZX05056-03-05)资助

摘　　要：采用恒电位阴极极化和线性极化法研究了天然海水中不同动态条件、不同初始保护电位下,阴极保护初期碳钢表面钙质沉积层的形成规律。扫描电镜(SEM)和能谱X-射线分析(EDX)分析了保护后碳钢表面的产物。结果表明:-800 mV(vs.SCE,下同)保护电位下,在静态和动态海水中碳钢表面形成的钙质沉积层质量都较差;-900 mV保护电位下,静态海水中形成致密的钙质沉积层,动态下钙质沉积层形成困难;-1 000 mV保护电位下,静态和动态海水中都形成良好的钙质沉积层。随流速增大,阴极保护电流密度显著增大,钙质沉积层中Ca/Mg比值增加;动态条件下,较负的保护电位,有利于阴极保护初期钙质沉积层的形成。Potentiostatic cathodic polarization and linear polarization were used to study the formation of calcareous deposits on the carbon steel in the initial period of cathodic protection in the natural seawater under the different dynamic conditions and the different protection potentials.Scanning electric microscope（SEM） and energy dispersive x-ray（EDX） were used to analyse the products on the carbon steel surface after polarization.The results showed that the calcareous deposits formed on the carbon steel surface was poor under the potential of-800 mV（vs.SCE,similarly hereinafter） in either static or dynamic seawater and compact calcareous deposits was formed under-900 mV potential on the static state,but the formation was difficult under the dynamic state and compact calcareous deposits was formed under-1 000 mV potential on either static or flowing state.The cathodic protection current density and the Ca/Mg ratio of the deposits obviously increased along with the increasing of flowing speed.Under the dynamic condition,more negative protection potential was advantageous to the calcareous deposits formation in the cathodic protection initial period.

关 键 词：阴极保护 保护电位 动态海水 钙质沉积层 

分 类 号：TG174.41[金属学及工艺—金属表面处理]