摘要
针对X70管线钢在HAc-CO2共存环境中的顶部腐蚀行为,利用高温高压冷凝反应釜进行不同含量醋酸的顶部腐蚀试验,研究腐蚀速率随醋酸浓度变化的影响。通过扫描电镜(SEM)和能谱分析(EDS)分析了腐蚀产物膜的微观形貌和成分。利用电化学冷凝反应釜研究了X70管线钢随HAc浓度变化的电化学腐蚀规律。结果表明,HAc含量越大,pH越小,腐蚀产物膜的保护性变差,导致X70管线钢的腐蚀速率增大;HAc含量升高,腐蚀电位向正向偏移,阴极反应电流增大,表明HAc的添加促进了阴极反应过程;低频感抗弧的出现是由于中间吸附产物的形成和溶解,从而影响FeCO3膜的形成和沉积。
Top-of-line corrosion behavior of X70 pipeline steel in HAc-CO2 environment was researched.Simulation laboratory experiment was performed in high temperature and high pressure condensation autoclave to research the effect of HAc concentration on X70 corrosion.SEM and EDS were used to analyze the morphology and characteristics of corrosion scales formed in various HAc concentrations.In addition,the electrochemical behavior of X70 pipeline steel was studied using electrochemical condensation autoclave.With addition of HAc,the corrosion rate increased with the increase of HAc concentration.It was attributed to the fact that HAc degraded the formation of protective FeCO3 scale due to the decrease of pH.In high acetic acid concentration environment,the corrosion potential was shifted toward more positive values,which was due to the increase of cathodic current.It can be deduced that HAc promotes the cathodic process.The adsorbed intermediate product resulted in the inductive loop,which affected the formation and deposit of FeCO3.
出处
《腐蚀与防护》
CAS
北大核心
2015年第8期700-705,共6页
Corrosion & Protection
基金
国家科技重大专项基金(2011ZX05056)
