目的 研究胡萝卜茎叶提取物（DCSLE）在硫酸介质中对碳钢的腐蚀抑制作用及机理。方法 通过超声辅助的手段，用水浸提获得DCSLE，利用红外光谱（FTIR）对其含有的主要官能团进行表征。在25~40 ℃下，采用失重法、电化学极化和阻抗法（EIS）评价DCSLE在0.5 mol/L H2SO4溶液中对碳钢的缓蚀性能，并讨论了其缓蚀机理。结果 DCSLE对碳钢在0.5 mol/L H2SO4溶液中的腐蚀具有良好的抑制效果，其缓蚀效率随浓度的增加而增加，随温度的增加而先增加后降低（40 ℃<25 ℃<30 ℃<35 ℃），35 ℃下，质量浓度为0.6 g/L时，缓蚀效率为92.85%。电化学测试表明，DCSLE是混合型缓蚀剂，但主要是抑制阴极的反应。其缓蚀机理是：DCSLE以物理和化学混合吸附的方式吸附在碳钢表面，形成一层保护膜，从而阻止酸溶液的侵蚀，且吸附遵循Langmuir吸附等温模型。扫描电镜（SEM）观察到加入DCSLE后，碳钢的腐蚀得到了明显控制。结论 DCSLE可以有效抑制碳钢在0.5 mol/L H2SO4溶液介质中的腐蚀，是一种具有广泛应用前景的天然绿色缓蚀剂。

The paper aims to study the inhibitive action of DCSLE on carbon steel in sulfuric acid medium. DCSLE were obtained by soaking and ultrasonic method with water as solvent and its main functions were characterized by FTIR. The inhibition effect of DCSLE on carbon steel corrosion in 0.5 mol/L H2SO4 solution was studied by weight loss method, potentiodynamic curves and electrochemical impedance spectroscopic (EIS) at 25~40 ℃ and the corresponding corrosion mechanism was discussed. The results showed that DCSLE had a good inhibition effect on carbon steel in 0.5 mol/L H2SO4 solution. Its inhibition efficiency increased with increase of concentration, and decreased with the increase of (40 ℃< 25 ℃< 30 ℃< 35 ℃). The inhibition performance reached to 92.85% with 0.6 g/L at 35 ℃. The electrochemical test showed that DCSLE was a mixed inhibitor which mainly inhibited the cathode reaction. The inhibition mechanism of DCSLE was that DCSLE was adsorbed on the surface of carbon steel by a mixture of physical and chemical adsorptions, forming a protective film to prevent the corrosion of acid solution, and the adsorption followed the Langmuir adsorption isotherm model. SEM showed that the corrosion of carbon steel was obviously controlled by adding DCSLE. The DCSLE can effectively inhibit the corrosion of carbon steel in 0.5 mol/L H2SO4 solution. It is a natural green corrosion inhibitor with wide application prospects.