温度和湍流对Cr合金钢环烷酸腐蚀的影响

Influence of Temperature and Turbulence on Naphthenic Acid Corrosion of Chromium Alloy Steel

对环烷酸腐蚀控制机制分析推测高温高流速下lnv与(-1/T)间的规律。对API581中Cr合金钢的腐蚀数据进行分析及模拟实验。结果表明:lnv-(-1/T)之间存在线性规律,应用lnv-(-1/T)线性规律可以较准确预测不同温度下Cr合金钢的平均环烷酸腐蚀速率。根据Fluent模拟得到不同条件下腐蚀试样表面的湍流分布,将试样表面湍流分布与表面3D腐蚀深度关联后可明确湍流强度会显著影响局部腐蚀深度。在2%弱湍流区,局部最大腐蚀深度与总平均腐蚀深度比值仅为1.56,但在8%湍流强度下,两者比值可大于3.7,影响程度随湍流强度的增加呈曲线快速提高。

Analysis on dynamic control mechanism of naphthenic acid corrosion indicated that the liner relationship between lnvand（-1/T）under high temperature and high flow rate.Analysis on corrosion data of Cr steel in API581 and the simulation experiment results both verify the linear relationship between lnvand（-1/T）.The relationship between lnvand（-1/T）can be applied to predict the average naphthenic acid corrosion rate of Cr steel under different temperature.Turbulence distribution on the specimens can be obtained through simulation by the software of Fluent.Correlations between turbulence distribution and local surface 3Dcorrosion depth on the specimens prove that turbulence intensity can significantly influence the local corrosion depth.The ratio between local max corrosion depth and average corrosion depth in 2%turbulence area was only 1.56,but in 8%turbulence area,the ratio can reach above 3.7times,the influence of turbulence on local corrosion depth increases with the turbulence intensity.