镍基合金在含H_2S/CO_2环境下的电化学腐蚀行为研究  

ELECTROCHEMICAL CORROSION BEHAVIOR OF Ni-BASED ALOYS IN AQUEOUS SOLUTION CONTAINING H_2S/CO_2

作　　者：赵雪会[1] 白真权[1] 尹成先[1] 魏斌[1] 尹志福[2] 

机构地区：[1]中国石油天然气集团公司石油管材研究所,西安710065 [2]西安交通大学材料学院,西安710049

出　　处：《腐蚀科学与防护技术》2009年第6期526-529,共4页Corrosion Science and Protection Technology

基　　金：中石油基金项目(2008D-2404)

摘　　要：采用电化学阳极循环极化曲线、交流阻抗技术分别研究了3种镍基耐蚀合金在饱和CO2的NaCl溶液中和加入H2S的体系中的电化学腐蚀行为.结果表明:在Cl-浓度为50 g/L的NaCl溶液中,3种材料的点蚀电位存在明显差异,Inconel 625点蚀电位最高;循环极化结果显示Inconel 625合金的滞后环最小,其保护电位(或再钝化电势)相对较高,表明其耐局部腐蚀性能优于其它两种材料;EIS表明阻抗谱均有明显的容抗弧特征,不含硫时3种材料显示单一的容抗弧,在CO2+H2S共存时低频显示扩散阻抗控制,Inconel 625均具有相对较大的极化电阻.The corrosion behavior of three Ni-based alloys was investigated in 50 g/L NaCl solution containing H2S/CO2 by polarization curve,anodic circulation curve and electrochemical impedance. The results showed that the pitting potential of different materials had obvious difference in the test conditions, and the pitting potential of Inconel 625 was the highest. Form circulation curves it follows that the Inconel 625 has the least encircled area and higher protection potential, which indicated that the corrosion resistance of Inconel 625 was superior to the others. EIS measurements indicate that the Nyquist plot of the three alloys is composed of single capacitance loop in the solutions without H2S. When H2S coexists with CO2, the plot revealed the corrosion characteristics of diffuse control at low frequencies. The capacitance loop radius of Inconel 625 was correspondingly the biggest.

关 键 词：镍基合金 腐蚀行为 点蚀 电化学阻抗谱 

分 类 号：TG172.9[金属学及工艺—金属表面处理]