高级检索

    高温高Cl-含量环境中H2S/CO2分压对超级双相不锈钢UNS S32750点蚀行为的影响

    Effects of H2S/CO2 Partial Pressures on Pitting Behavior of Super Duplex Stainless Steel UNS S32750 in a Environment of High Temperature and High Chloride Content

    • 摘要: 在高温、高Cl-含量及不同H2S/CO2分压条件下对超级双相钢UNS S32750进行了腐蚀浸泡试验,并采用失重法、激光共聚焦显微镜、X-射线光电子能谱(XPS)分析了超级双相不锈钢UNS S32750的均匀腐蚀速率、点蚀形貌和表面钝化膜组成。结果表明:在试验条件下当H2S/CO2分压不大于30 kPa/150 kPa时,超级双相不锈钢UNS S32750具有良好的耐均匀腐蚀和点蚀性能;但当H2S/CO2分压为100 kPa/500 kPa时,H2S造成了钝化膜的局部破坏,引发阳极性溶解,使超级双相不锈钢UNS S32750发生点蚀;钝化膜主要由FeS2、NiO、NiS、Cr2O3及Fe (OH)2组成。

       

      Abstract: Corrosion immersion tests were conducted on super duplex stainless steel (SDSS) UNS S32750 in a environment of high temperature, high chloride concentration and different partial pressures of H2S and CO2. The general corrosion rate, pitting corrosion morphology of SDSS UNS S32750 and composition of passive film on its surface by the methods of mass loss, laser confocal microscopy and X-ray photoelectron spectroscopy (XPS) techniques. The results show that the SDSS UNS S32750 had a good general corrosion resistance and pitting corrosion resistance when the partial pressures of H2S and CO2 were no higher than 30 kPa and 150 kPa respectively under the test condition. When the partial pressures of H2S and CO2 were 100 kPa and 500 kPa respectively, pitting corrosion happened to the SDSS UNS S32750 due to the localized loss of the passive film and consequent anodic dissolution. The passive film was mainly composed of FeS2, NiO, NiS, Cr2O3 and Fe(OH)2.

       

    /

    返回文章
    返回