【摘要】 <正> 一、前言对于金属材料在高温燃气环境中所遭受的热腐蚀有多种研究方法,其中电化学方法颇具特色。本文作者曾将弱极化曲线拟合、微分极化电阻技术应用于热腐蚀研究,为快速评价合金耐蚀性能和监控热腐蚀过程提供了有效手段。交流阻抗技术能有效地研究反应机理和其它有关电化学现象,应用于研究熔盐热腐蚀尚在起步阶段。Farrel等和Gao等分别应用交流阻抗技术研究了N75合金及Ni-Co、铁基800合金的热腐蚀行为,发现腐蚀反应受扩散控制,但更多还原

【Abstract】 An electrochemical impedance study of hot corrosion of FE-Cr alloys in molten （Na, K, Li）₂SO₄ salts at 700℃ has been carried out. It is shown that the corrosion of Fe-5Cr alloy is a diffusion-controlled process, while the corrosion of Fe-20Cr and Fe-25Cr alloys changes from the initial diffusion-controlled reaction to a non-diffusion-controlled one. An adequate electrical equivalent circuit has been proposed and is employed to fit the experimental impedance data. The fitting results show that the charge-transfer resistance （R_t） increases with the chromium content in the alloys, which means that chromium can improve the hot corrosion resistance.更多还原