20碳钢在模拟油田水中的流动促进腐蚀行为  

Corrosion behavior of 20 carbon steel pipe in simulated oilfield water

作　　者：王美玲 胡莹 张志浩 陈迎锋 陆永浩 WANG Mei-ling;HU Ying;ZHANG Zhi-hao;CHEN Ying-feng;LU Yong-hao(National Centre for Material Service Safety,University of Science and Technology of Beijing,Beijing 100083, China;Xi'an Changqing Technology Engineering Co Ltd,Xi'an 710018,China)

机构地区：[1]北京科技大学国家材料服役安全科学中心,北京100083 [2]西安长庆科技工程有限责任公司,陕西西安710018

出　　处：《材料热处理学报》2018年第12期84-90,共7页Transactions of Materials and Heat Treatment

基　　金：国家重大科学仪器设备开发专项(2011YQ14014505);中央高校基本科研业务费(FRF-OT-17-016)

摘　　要：依据长庆油田采出水样成分分析结果,模拟了油田管道内壁实际服役水环境,研究了20碳钢在模拟油田水中的流动促进腐蚀行为。结果表明:在流速为0.2 m/s的高矿化度油田水介质中,20碳钢发生了铁素体选择性溶解腐蚀,平均腐蚀速率约为2.6749 mm/a,属极其严重腐蚀;腐蚀早期,在水介质的冲刷下,从溶液中沉积的FeCO_3/Fe_2O_3纳米晶层难以快速在碳钢表面沉积成完整的保护层,铁素体不断纵向溶解,在碳钢表面形成沿原始珠光体条带方向的腐蚀沟;随着腐蚀的不断进行,腐蚀沟底部的纳米晶层不断沉积长大,形成致密的"内层纳米晶层+外层氧化物颗粒/残留渗碳体"混合双层腐蚀膜,腐蚀纵向发展得以抑制,转为沿着横向扩张;腐蚀后期,盐类特别是CaCO_3开始形核长大,在最外层表面生成较厚的粘土状的腐蚀垢层,垢下局部腐蚀腐蚀加剧,造成油田20碳钢管道局部腐蚀穿孔。Based on the analysis results of produced water in Changqing Oilfield, the actual service water environment of the inner wall of oilfield pipeline was simulated, and the corrosion behavior of 20 carbon steel in simulated oilfield water was studied. The results show that the ferrite selective dissolution corrosion of the 20 carbon steel occurs in high salinity oilfield water medium with a flow rate of 0.2 m/s, and the average corrosion rate is about 2.6749 mm/a, indicating that the corrosion is extremely serious. In the early stage of corrosion, under the scouring of water medium, the FeCO3/Fe2O3 nanocrystalline layer precipitated from solution cannot rapidly form a complete protective layer on the surface of 20 carbon steel. The ferrite is constantly dissolved in the longitudinal direction, forming a corrosion groove along the direction of the original pearlite strip on the surface of carbon steel. With the development of the corrosion process, the nanocrystals(FeCO3 and Fe2O3) deposits at the bottom of earlier corrosion grooves and grows continuously, forming a dense "inner nanocrystalline layer and the outer oxide particle or residual cementite" mixed double corrosion layer, and the longitudinal corrosion development is inhibited, rendering the corrosion spread horizontally. At the later stage of corrosion, the salts, especially CaCO3, begin to nucleate and form a thick clay-like corrosion scaling layer on the outermost surface, and the local corrosion is aggravated by under-deposit corrosion, resulting in the local corrosion perforation of 20 carbon steel pipeline in oil field.

关 键 词：20碳钢 高矿化度 流动促进腐蚀 选择性溶解 

分 类 号：TG142.3[一般工业技术—材料科学与工程]