摘要
利用高压釜研究了X60和X70钢在饱和H2S及CO2 分压为 2 MPa的 NACE溶液中高温高压腐蚀环境下的腐蚀行为.研究结果表明:1) 在所研究的温度范围内,两种钢均表现出较高的腐蚀速率,且伴有不同程度的点蚀或蚀坑群,其中CO2 引发点蚀,H2S会加速阴极和阳极的反应速率,造成严重点蚀.2) 随着温度的升高,武钢 X60的腐蚀速率呈上升→下降→上升的趋势,宝钢X70的腐蚀速率呈下降→上升→下降的趋势.3) 两种钢的表面腐蚀产物膜结构主要为铁的硫化物.4) Cl-为点蚀的“激发剂”,并且在点蚀坑内富集,导致局部Cl-浓度差不同,形成电偶腐蚀,促进点蚀发生.
Under high-temperature and high-pressure environment,the pitting behavior of steel X60 and X70 in NACE solution saturated with hydrogen sulfide (H_2S) and carbon dioxide (CO_2),with partial pressure of 2 MPa is investigated using autoclave. The results show that 1) within the temperature range (adopted) for the research,both sorts steel are severely of corroded with different degree pitting or pitting groups,where CO_2 causes pitting corrosion and H_2S accelerates cathode and anode reaction,resulting in severe pitting corrosion;2) with temperature increasing,the variation of corrosion rate of X60 and X70 takes the manner as increasing → decreasing → increasing and decreasing →increasing → decreasing,respectively;3) The main structure of corrosion scales on the two kinds of pipelines are iron sulfide;4) Cl^- is the “exciter” of pitting and its is rich-gathered in pits so that causes different localized Cl^- concentration gradients and galvanic corrosion,with enhancing pitting,is formed.
出处
《兰州理工大学学报》
CAS
北大核心
2005年第1期31-34,共4页
Journal of Lanzhou University of Technology
基金
甘肃省自然科学青年基金(ZQ 95 019)
