应用电化学弱极化法和原子力显微镜(AFM)研究了咪唑啉衍生物类缓蚀剂在模拟深层气井水溶液中对碳钢的二氧化碳腐蚀的抑制效果和缓蚀作用机理.结果表明,在不同的实验温度下,该缓蚀剂均具有较好的缓蚀性能,属于以抑制阳极为主的混合型缓蚀剂.该咪唑啉衍生物在碳钢表面上的吸附遵从Langm iur方程.计算了该腐蚀体系热力学参数(ΔH°、ΔG°和ΔS°)以及腐蚀反应的活化能(Ea)和指前因子(A),并解释了实验结果.

The electrochemical method and atomic force microscope(AFM) were applied to study the inhibition mechanism of Im-D,an imidazoline derivate inhibitor,for mild steel in CO2 saturated solution.The imidazoline derivate can inhibit effectively CO2 corrosion,make the steel surface smoother and belongs to the anodic controlled mixed-type inhibitor.Its adsorption on the surface of mild steel is a spontaneous and exothermic process accompanied by the decrease of entropy and follows the Langmuir adsorption isothermal equation.The lower temperature will facilitate the process.The changes in the apparent activation energy(Ea) and the pre-exponential factor(A) of the corrosion reaction before and after the addition of inhibitor were also discussed.