7%Cr管线钢在含有CO_(2)盐溶液中的腐蚀行为研究

Research on corrosion behavior of 7% Cr pipeline steel in CO_(2) salt solution

利用失重法,结合显微形貌、能谱分析、X射线衍射、电化学测试等手段,分析了中铬钢在高温高压含有CO_(2)的盐溶液环境中腐蚀的萌生与发展,以及热处理工艺对中Cr钢的耐蚀性能影响规律。结果显示:7%Cr(质量分数)钢在有CO_(2)的盐溶液中的腐蚀以点蚀为开端,随后形成由Cr(OH)_(3)和FeCO_(3)组成的非晶态产物膜,产物膜外层有颗粒状FeCO_(3)附着,随着Cr(OH)_(3)的大量产生产物膜中部分FeCO_(3)溶解,随后CaCO_(3)沉淀填补了颗粒状FeCO_(3)溶解后留下的空隙。热处理后淬火试样耐蚀性最好,正火次之,轧制试样最差。

The weightlessness method,combined with microscopic morphology,energy spectrum analysis,X-ray diffraction,and electrochemical testing,was used to analyze the initiation and development of medium-Cr steel corrosion in a high-temperature and high-pressure salt solution environment containing CO_(2) and the effect of heat treatment process on the corrosion resistance of medium Cr steel.The results show that the corrosion of 7% Cr(mass%)steel in the salt solution with CO_(2) starts with pitting corrosion,and then an amorphous product film composed of Cr(OH)_(3) and FeCO_(3) is formed.The outer layer of the product film has granular FeCO_(3) attached.When large amount of Cr(OH)_(3) is produced,part of the FeCO_(3) in the product film is dissolved,and the precipitation of CaCO_(3) fills the gap left by the dissolution of granular FeCO_(3).After heat treatment,the quenched sample has the best corrosion resistance,the normalization is slightly worse,and the rolled sample is the worst.