温度对X65管线钢在含CO_(2)/H_(2)S油田模拟环境中腐蚀行为的影响

Effect of Temperature on Corrosion Behavior of X65 Pipeline Steel in Simulated Environments Containing CO_(2)/H_(2)S in Oil Fields

为了研究在含CO_(2)/H_(2)S环境中温度对X65管线钢腐蚀的影响,采用高温高压模拟集输管线工况环境进行腐蚀试验和电化学试验,并对X65管线钢在不同温度下的腐蚀行为进行分析。结果表明,随着温度的升高,均匀腐蚀速率呈现先增大后减小的趋势,温度达到80℃时,均匀腐蚀速率达到最大值,为0.4345 mm/a,此时试样表面腐蚀产物较为粗糙,生成腐蚀产物FeCO_(3)和FeS;随着温度的升高,X65管线钢腐蚀逐渐以H_(2)S腐蚀为主,腐蚀电流密度先增加后减小,与失重腐蚀试验结果相符,X65管线钢的容抗弧呈现一个时间常数且半径逐渐减小;在试验温度下试样表面都有CaCO_(3)生成,这可能与溶液中的Ca^(2+)含量高相关。

In order to study effect of temperature on corrosion of X65 pipeline steel in CO_2/H_(2)S environment,the corrosion behavior of X65 pipeline steel at different temperatures was analyzed through high-temperature and high-pressure simulated environmental corrosion and electrochemical tests.Results indicate that with the increase of temperature,the uniform corrosion rate shows a trend of first increasing and then decreasing.When the temperature reaches at 80℃,the uniform corrosion rate reaches its maximum value of 0.4345 mm/a.The surface corrosion products of the sample are relatively rough,generating the corrosion products FeCO_(3)and FeS.As the temperature increases,the corrosion of X65 pipeline steel gradually becomes dominated by H_(2)S corrosion,and the corrosion current density first increases and then decreases,which is consistent with the results of the weight loss corrosion test.The capacitance arc of X65 pipeline steel shows a time constant and the radius gradually decreases.At the experimental temperature,CaCO_(3)was generated on the surface of the sample,which may be related to the high Ca^(2+)content in the solution.