Department of Chemical Engineering and Metallurgy, University of Sonora, Hermosillo 83000, Mexico.
Corrosion y Proteccion (CyP), Buffon 46, Mexico City 11590, Mexico.
Molecules. 2022 Aug 16;27(16):5209. doi: 10.3390/molecules27165209.
The most practical and economical way to combat the problems derived from CO corrosion (sweet corrosion) is the use of corrosion inhibitors of organic origin. Its main protection mechanism is based on its ability to adsorb on the metal surface, forming a barrier between the metal surface and the aggressive medium. However, despite its excellent performance, its inhibition efficiency can be compromised with the increase in temperature as well as the shear stresses. In this study, the use of an inorganic inhibitor is proposed that has not been considered as an inhibitor of sweet corrosion. The reported studies are based on using LaCl as a corrosion inhibitor. Its behavior was evaluated on 1018 carbon steel using electrochemical measurements, such as potentiodynamic polarization curves, open-circuit potential measurements, linear polarization resistance measurements, and electrochemical impedance. The results showed an inhibition efficiency of the sweet corrosion process greater than 95%, and that the inhibition mechanism was different from the classic corrosion process in CO-free electrolytes. In this case, it was observed that the inhibitory capacity of the La cations is based on a CO-capture process and the precipitation of a barrier layer of lanthanum carbonate (La(CO)).
防治 CO 腐蚀（甜腐蚀）问题最实用和最经济的方法是使用有机来源的腐蚀抑制剂。其主要保护机制基于其在金属表面上吸附的能力，在金属表面和腐蚀性介质之间形成屏障。然而，尽管其性能优异，但随着温度的升高以及剪切应力的增加，其抑制效率可能会受到影响。在这项研究中，提出了使用一种无机抑制剂的方法，该抑制剂以前并未被认为是甜腐蚀抑制剂。所报道的研究基于使用 LaCl 作为腐蚀抑制剂。使用电化学测量（如动电位极化曲线、开路电位测量、线性极化电阻测量和电化学阻抗）评估 1018 碳钢上的行为。结果表明，对甜腐蚀过程的抑制效率大于 95%，并且抑制机制与无 CO 电解质中的经典腐蚀过程不同。在这种情况下，观察到 La 阳离子的抑制能力基于 CO 捕获过程和碳酸镧（La(CO)）阻挡层的沉淀。
