目的 开发一种能够在热硫酸介质中长期保护316L不锈钢的新型复合涂层。方法 使用化学氧化法制备一次掺杂聚苯胺（PANI），通过脱掺杂-二次掺杂制备十二烷基苯磺酸（DBSA）掺杂的二次掺杂聚苯胺，并添加环氧树脂（EP）作为成膜剂制备PANI/EP复合涂层。通过傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和X射线能谱（EDS）等方法，对材料的官能团、结构和形貌进行表征，用电化学测试法和划痕浸泡实验测试PANI/EP复合涂层的耐蚀性能，并对复合涂层的保护机理进行探讨。结果 在50、60 ℃的1 mol/L硫酸溶液中，PANI/EP复合涂层试样的自腐蚀电位相对不锈钢显著提高，其中50 ℃时提高了560 mV，60 ℃时提高了450 mV，均达到不锈钢的钝化电位，阳极极化曲线电流密度下降了两个数量级。电化学交流阻抗测试表明，涂覆涂层后，试样的阻抗模值明显增大。划痕浸泡试验表明，在50 ℃的1 mol/L硫酸溶液中浸泡一周后，PANI/EP复合涂层试样没有发生脱落，且划痕处几乎没有腐蚀，主要原因是涂层促使不锈钢表面生成了稳定的钝化膜。结论 在中温硫酸溶液中，PANI/EP复合涂层对不锈钢同时提供物理屏蔽作用和阳极保护作用，有良好的防腐蚀保护效果。

The work aims to develop a novel composite coating to protect 316L stainless steel in hot sulfuric acid solution for long term. The primary doped polyaniline (PANI) was prepared by chemical oxidation method, dodecylbenzenesulfonic acid (DBSA) doped polyaniline was obtained by dedoping-redoping process, and epoxy resin (EP) was used as the film former to prepare PANI/EP composite coating. The functional groups, structures and morphologies of the materials were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The electrochemical tests and scratch immersion tests were used to evaluate the anti-corrosion performance of PANI/EP composite coating, and the protection mechanism of the composite coating was discussed. In 1 mol/L sulfuric acid solution of 50 ℃ and 60 ℃, the corrosion potential of the PANI/EP coated sample increased significantly by 560 mV and 450 mV at 50 ℃ and 60 ℃ respectively compared to stainless steel, reaching the passivation potential range of stainless steel. The current density of anodic polarization curve decreased by two orders of magnitude, and the EIS test showed that the impedance modulus of the PANI/EP coated sample increased significantly. The scratch immersion test showed that after immersed in 1 mol/L sulfuric acid solution of 50 ℃ for one week, the PANI/EP composite coating did not fall off, and there was almost no corrosion at the scratches. The main reason was that the stable passive film formation was promoted by coating. Therefore, the PANI/EP composite coating can provideboth physical shielding and anodic protection to the stainless steel in medium temperature sulfuric acid solution and have good corrosion protection effect.