7%Cr管线钢在含有CO2盐溶液中的腐蚀行为研究

摘要：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CO2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CO2的盐溶液中的腐蚀以点蚀为开端，随后形成由Cr(OH)3和FeCO3组成的非晶态产物膜，产物膜外层有颗粒状FeCO3附着，随着Cr(OH)3的大量产生产物膜中部分FeCO3溶解，随后CaCO3沉淀填补了颗粒状FeCO3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。

Research on corrosion behavior of 7% Cr pipeline steel in CO2 salt solution

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 CO2 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 CO2 starts with pitting corrosion, and then an amorphous product film composed of Cr(OH)3 and FeCO3 is formed. The outer layer of the product film has granular FeCO3 attached. When large amount of Cr(OH)3 is produced, part of the FeCO3 in the product film is dissolved, and the precipitation of CaCO3 fills the gap left by the dissolution of granular FeCO3. After heat treatment, the quenched sample has the best corrosion resistance, the normalization is slightly worse, and the rolled sample is the worst.