不同腐蚀条件下高强15Cr马氏体不锈钢表面状态表征  

Surface State Characterization of High-strength 15Cr Martensitic Stainless Steel under Different Corrosion Conditions

作　　者：张福祥[1] 吕祥鸿[2] 杨向同 赵国仙 巴旦 张双双 

机构地区：[1]塔里木油田分公司油气工程研究院,新疆库尔勒841000 [2]西安摩尔石油工程实验室股份有限公司,陕西西安710065

出　　处：《材料科学与工程学报》2015年第6期804-809,共6页Journal of Materials Science and Engineering

基　　金：国家科技重大专项子课题资助项目(超深超高压高温气井试油完井及储层改造配套技术研究2011ZX05046-04)

摘　　要：通过模拟酸化及生产工况条件下的鲜酸、残酸及地层水CO2腐蚀试验,研究高强15Cr马氏体不锈钢在不同条件下的腐蚀行为,利用电化学测试技术,探讨其在不同腐蚀环境中的表面(钝化)状态,并对其耐蚀性进行表征。结果表明:高强15Cr马氏体不锈钢在鲜酸中处于活化状态,均匀腐蚀速率极大,并且出现明显局部腐蚀;在残酸及地层水CO2腐蚀环境中,高强15Cr马氏体不锈钢处于钝化状态,其钝化膜具有双极性n-p型半导体特征,均匀腐蚀轻微,试样表面未出现明显局部腐蚀;相比于地层水CO2腐蚀环境,残酸溶液的pH值较低,高强15Cr马氏体不锈钢稳定钝化区范围显著减小,外层钝化膜掺杂浓度升高,平带电位正移,钝化膜的致密度下降,耐蚀性降低。在高强15Cr马氏体不锈钢油管的使用过程中,酸化压裂的鲜酸腐蚀是造成其发生腐蚀,特别是点蚀的主要原因。Through simulating the corrosions in live acid,spent acid and stratum water by CO2,the corrosion performance of high-strength 15 Cr martensitic stainless steel was investigated.The surface(passivation)states and corrosion resistance of the high-strength 15 Cr martensitic stainless steel in different corrosion environments were analyzed based on the electrochemical measurements of the corresponding systems.The result shows that the high-strength 15 Cr martensitic stainless steel is in activation state in the live acid solution,the uniform corrosion rate is extremely high,and the local corrosion occurs obviously.In spent acid and stratum water CO2 corrosion environments,this martensitic stainless steel is in a passive state,and the passive film has the characteristics of n-pbipolar semiconductor with slight uniform corrosion,and without obvious local corrosion.Compared with stratum water CO2 corrosion environment,the pH value of spent acid solution is lower,and the scope of stable passive zone of the stainless steel decreases remarkably.Besides,the doping concentration of outer-layer passive film rises,and the flat band potential moves positively,while the density of passive film declines,and the corrosion resistance decreases.In the process of using the high-strength 15 Cr martensitic stainless steel tubing,live acid corrosion during acid fracturing is the main cause of corrosion,especially the pitting corrosion.

关 键 词：高强15Cr马氏体不锈钢 钝化 活化 掺杂浓度 

分 类 号：TG142.71[一般工业技术—材料科学与工程]