用于集输管线的0.5Cr 钢在模拟塔里木油田环境中的H2S/CO2 腐蚀行为研究

运用腐蚀失重和四点弯曲实验，参照NACE 0177-2005标准研究了用于集输管线的0.5Cr 钢在模拟塔里木油田腐蚀环境中的H₂S/CO₂腐蚀行为。结果表明，0.5Cr 钢在CO₂腐蚀环境中具有极高的均匀腐蚀速率，H₂S腐蚀性气体的存在显著降低了材料的均匀腐蚀速率。在CO₂分压为2MPa、H₂S分压为0.5MPa 时，腐蚀速率仅为0.1523 mm/a，表现出良好的抗均匀腐蚀和局部腐蚀能力。在H₂S和CO₂共存的环境条件下，0.5Cr 钢表面的腐蚀产物为FeS，未出现CO₂腐蚀产物成分FeCO₃。在该模拟条件下，H₂S的腐蚀占主导作用。同时模拟油田工况条件的抗H₂S应力腐蚀开裂实验表明，0.5Cr 钢具有良好的抗H₂S应力腐蚀开裂能力。

Experimental study on corrosion behaviors of H2S and CO2 to 0.5 Cr steel used in gathering pipeline at simulated environment of Tarim Oilfield

According to the NACE 0177-2005 standard, the corrosion behaviors of H₂S and CO₂ to 0.5Cr steel used in gathering pipeline at the simulated environment of Tarim Oilfield were studied with the mass loss and four-point bent test. The results showed that the 0.5Cr steel had very high uniform corrosion rate at CO₂ corrosion environment, and the occurrence of H₂S reduced the corrosion rate of 0.5Cr steel. The corrosion rate of 0.5Cr steel was only 0.1523 mm per year, when the partial pressure of CO₂ was 2 MPa and partial pressure of H₂S was 0.5 MPa. Under those conditions, 0.5Cr steel presented the superior uniform and local corrosion resistance. At the simulated CO₂ and H₂S coexistence environment, the corrosion product was FeS, and H₂S electrochemical corrosion dominated the corrosion course of 0.5Cr steel. The test showed that 0.5Cr steel had the favorable resistance to H₂S stress corrosion cracking at the simulated environment.