In this research, to enhance the corrosion resistance of low carbon steel in the H₂SO₄ solution, the leech extract as a novel bio-inhibitor was utilized. Electrochemical tests were applied to investigate corrosion characteristics of steel in the corrosive acid solution. Moreover, the atomic force microscopy (AFM) and the field emission scanning electron microscopy (FE-SEM) techniques were performed for studying the morphology of corroded steel surfaces. Based on the polarization data, the inhibition efficiency raised from 75 to 91% in the presence of the inhibitor with concentrations of 1–3 g/L. However, electrochemical impedance spectroscopy test results showed that such an increase was about 66–84%. When the test temperature increased to 40°C, the inhibition efficiency reduced from 91 to 44%. Polarization test results explained that the adsorption of leech extract molecules on metallic surfaces operated as a mixed inhibitor. In this situation, the measured activation energy increased from 65.28 to 152.93 kJ/mol.K. In addition, based on the obtained electrochemical data, leech extract molecules were adsorbed on steel surfaces through the Langmuir adsorption mechanism. Both FE-SEM and AFM micrographs from corroded metallic surfaces depicted that when the utilized bio-inhibitor was added to the H₂SO₄ solution a much smoother metal surface would be observed.

在这项研究中，要提高低碳钢在H ₂ SO _4中的耐腐蚀性溶液中，利用了水as提取物作为新型生物抑制剂。电化学测试用于研究钢在腐蚀性酸溶液中的腐蚀特性。此外，原子力显微镜（AFM）和场发射扫描电子显微镜（FE-SEM）技术用于研究腐蚀的钢表面的形貌。根据极化数据，在浓度为1-3 g / L的抑制剂存在下，抑制效率从75％提高到91％。但是，电化学阻抗谱测试结果表明，这种增加约为66–84％。当测试温度升高至40°C时，抑制效率从91％降低至44％。极化测试结果解释说，水molecules提取物分子在金属表面上的吸附起着混合抑制剂的作用。在这种情况下，测得的活化能从65.28 kJ / mol.K增加到152.93 kJ / mol.K。另外，基于获得的电化学数据，通过Langmuir吸附机理将水ech提取物分子吸附在钢表面上。腐蚀金属表面的FE-SEM和AFM显微照片均显示，当将所使用的生物抑制剂添加到H中时₂ SO ₄溶液将观察到更光滑的金属表面。