X65钢和3Cr钢作为海底管道用钢抗CO2腐蚀性能研究

摘要

The high-pressure high temperature au toclave was used to simulate the typical corrosion environment for oil and gas pipeline, and the CO2 corrosion resistance of X65 and 3Cr steels applied to subsca pipeline was researched.The corrosion rates of both X65 and 3Cr steels were low in mild corrosion environment, so we could choose X65 steel in this environment.With temperature and CO2 par tial pressure increasing, the CO2 corrosion resistance of 3Cr was superior to X65 steel; the average corro sion rate of 3Cr steel was obviously lower than X65 in the middling corrosion environment and 3Cr steel can avoid local corrosion in the middling and severe corrosion environments, so the 3Cr steel was more appropriate than X65 steel in such corrosion environ ment.The corrosion product scale enriched with Cr element was formed on the surface of the steel to protect the matrix from corrosion, which was the main reason that the CO2 corrosion resistance of 3Cr steel was superior to that of X65.%用高温高压反应釜模拟油气输送管道典型腐蚀环境,研究X65钢和3Cr钢作为海底管道用钢的抗CO2腐蚀性能.在温和腐蚀环境,X65钢与3Cr钢的平均腐蚀速率均较低,使用X65钢是安全的.随着温度和CO2分压提高,与X65钢相比3Cr钢表现出更优越的抗CO2腐蚀性能:在中等腐蚀环境3Cr钢平均腐蚀速率较X65钢大幅降低,在中等和苛刻腐蚀环境3Cr钢可有效抑制局部腐蚀的发生;在这样的腐蚀条件下,3Cr钢作为海底管道用钢较X65钢安全.3Cr钢较X65钢抗CO2腐蚀性能提高的主要原因是表面形成了富Cr的腐蚀产物膜,结构致密,对基体起到了有效的保护作用.