熔融盐热腐蚀的电化学阻抗模型

研究了Ｎｉ３Ａ，ＦｅＡｌ合金及溅射ＣｏＣｒＡｌＹ涂层在熔融盐腐蚀过程中的阻抗谱特征，根据合金在熔融盐腐蚀过程进行了表面氧化膜形成的特点，并结合阻抗实验结果，提出金属材料在熔融盐腐蚀过程中的电化学阻抗模型，当合金表面形成完整，致密的氧化膜时，其阻抗谱呈双容抗弧特征；反之，当氧化膜疏松，多孔时，则表现为受氧化剂扩散控制；当合金表面氧化膜不完整的涂层遭受局部较快腐蚀时，则通常表现为双容抗弧特征。

ELECTROCHEMICAL IMPEDANCE MODELS FOR MOLTEN SALTS INDUCED CORROSION

The electrochemical impedance technique was employed to study the corrosion behaviors of Ni3Al, FeAl and sputtered CoCrAlY coating in molten salts. Electrochemical impedance models for the molten salt corrosion have been proposed by taking account of the experimental results and the characteristics of the growth of the oxide scales. The electrochemical impedance shows the characteristics of two capacitance loops when a continuous protective scale grows on the alloy surface. Conversely, the corrosion process is controlled by the diffusion of oxidants when a porous scale develops. When the alloy forms a discontinuous scale and a coating suffers from localized fast corrosion, the electrochemical impedance also has the characteristics of two capacitance loops.