{首页主词},&

硫脲基咪唑啉季銨鹽緩蝕劑對X80管線鋼腐蝕的影響

2021-04-23 15:41:43 作者：白云龍來源：中國腐蝕與防護學(xué)報分享至：

摘要

考察硫脲基咪唑啉季銨鹽（IM-S1）緩蝕劑對X80管線鋼在3種不同pH的模擬油田水溶液中的緩蝕性能。采用電化學(xué)極化曲線、電化學(xué)阻抗分析、SVET、表面形貌分析等方法，研究緩蝕劑在不同pH、不同溫度的模擬油田水溶液對X80管線鋼的緩蝕性能。極化曲線測試顯示，pH7.2環(huán)境中的腐蝕電流密度最小，其次是pH10.5，在pH3.5環(huán)境中的腐蝕電流密度最大；并隨溫度升高，腐蝕電流密度均有所升高。電化學(xué)阻抗的測試表明，在pH7.2模擬溶液條件下，所顯示的容抗弧直徑最大，且擬合結(jié)果中Rct明顯高于其他兩種測試條件。SVET分析顯示，在pH7.2的測試條件下，管線鋼表面吸附成膜性要優(yōu)于其他兩種測試條件；且離子電流密度隨時間呈下降趨勢，說明緩蝕劑粒子更適宜在此pH值條件下吸附成膜。根據(jù)SEM分析，可以明顯看出，IM-S1緩蝕劑在中性條件的緩蝕效果要優(yōu)于pH3.5和pH10.5條件的緩蝕作用效果。IM-S1緩蝕劑更適宜在中性條件下使用，并且在中低溫（40~60 ℃）條件下具有良好的緩蝕效果。該類緩蝕劑在中性溶液條件的吸附成膜性要優(yōu)于酸性和堿性條件的成膜性，并且吸附成膜降低離子電流密度，從而有效降低腐蝕反應(yīng)速率。

關(guān)鍵詞：硫脲基咪唑啉季銨鹽 ; 緩蝕劑 ; 模擬油田水溶液 ; X80管線鋼 ; 電化學(xué) ; SVET

Abstract

The effect of the thiourea base imidazoline quaternary ammonium salt corrosion inhibitor on the corrosion performance of X80 pipeline steel in three simulated oil-field waters with different pH was assessed by means of polarization curve measurement, electrochemical impedance spectroscopy （EIS） and scanning vibrating electrode technique （SVET） as well as characterization of corrosion morphology and corrosion products. Polarization curve measurement showed that the corrosion current density was the lowest in the water of pH7.2, followed by pH10.5, while the corrosion current density was the highest in the water of pH3.5，and as the temperature increased, the corrosion current density also increased. The EIS results showed that the diameter of capacitive reactance arc was the largest in the water of pH7.2, accordingly, the Rct in the fitting result was significantly higher than those in the other two waters. The SVET analysis revealed that the adsorption film formation on the surface of pipeline steel in the water of pH7.2 was better than in the other two waters, while the ion current density decreased with time, indicating that the corrosion inhibitor molecule is more suitable for the case in the water of pH7.2. The film formation by adsorption reduces the ion current density, thereby effectively reduces the corrosion reaction rate. In conclusion, the corrosion inhibitor is much suitable for use in neutral waters and it has good corrosion inhibition effect in the temperature range of 40~60 ℃。

Keywords： IM-S1 ; corrosion inhibitor ; simulated oil-field water ; X80 pipeline steel ; electrochemistry ; SVET