Biological macromolecule as an eco-friendly high temperature corrosion inhibitor for P110 steel under sweet environment in NACE brine ID196: Experimental and computational approaches

Thiol-ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment

l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor. The corrosion inhibition efficiency (η) for QS showed a first-increase-and-then-decrease trend with increasing Cys-GO concentrations. The optimum concentration of Cys-GO was 15 mg L-1, and the according η value was up to 90%. The Cys-GO adsorbed on the QS surface to form a protective barrier was responsible for the efficient corrosion inhibition. Langmuir adsorption isotherm model was fitted well with the experiment data, indicating a monolayer adsorption. Furthermore, the coordinate covalent bonds, π-back-donation effect, and electrostatic attraction were responsible for the Cys-GO adsorption on the QS surface.

Exploring the Effectiveness of Natural Food Flavors in Protecting Carbon Steel against CO2-Induced Corrosion

Two food flavors, furfuryl mercaptan (2-FFT) and difurfuryl disulfide (DFDS), were investigated as green corrosion inhibitors for the N80 steel in a CO2-saturated solution containing 3.5% NaCl. Experimental methods, quantum chemical calculations, and molecular dynamics simulation were employed to evaluate the effectiveness of 2-FFT and DFDS. The results of the study indicate that both 2-FFT and DFDS act as mixed corrosion inhibitors, with a dominant inhibition effect on the cathodic reaction. 2-FFT is physiochemically adsorbed on the steel surface in a tiled form through the furan ring and the - SH groups as adsorption sites. On the other hand, DFDS is chemisorbed on the steel surface through the - S-S- groups in a parallel manner. DFDS exhibits a higher tendency for electron transfer and stronger adsorption to steel compared to 2-FFT. Overall, this study highlights the potential of natural food flavors as effective and environmentally friendly corrosion inhibitors for carbon steel in CO2-saturated environments. The findings of this research can contribute to the development of sustainable and nontoxic corrosion inhibitors for the oil and gas industry.

Falcaria vulgaris leaves extract as an eco-friendly corrosion inhibitor for mild steel in hydrochloric acid media

Undoubtedly, metal corrosion is one of the most challenging problems faced by industries. Introducing corrosion inhibitors is a reasonable approach to protecting the metal surface. Due to environmental concerns and the toxicity of industrial organic corrosion inhibitors, researchers are continually exploring acceptable replacements. The current study focused on the application of Falcaria Vulgaris (FV) leaves extract to mitigate mild steel (MS) corrosion in a 1 M HCl environment. The polarization findings demonstrated that the corrosion current density decreased from 264.0 µA/cm² (for the sample submerged in the blank solution) to 20.4 µA/cm² when the optimal concentration of 800 ppm of FV leaves extract was added to the acid solution. Electrochemical impedance spectroscopy (EIS) analysis revealed an inhibition efficiency of 91.3% at this concentration after 6 h of immersion. It was determined by analyzing several adsorption isotherms that this corrosion inhibitor obeys the Frumkin isotherm. AFM, FE-SEM, and GIXRD surface analyses also supported the findings that adding FV leaves extract can reduce metal damage by adsorption on the metal surface.

Structural and Tribological Properties of Heat-Treated Stainless Steels against Abrasive and Lubricant Wear Conditions

The current paper investigates the effect of the heat treatment process on three grades of stainless steel alloys against the abrasive and the lubricant wear conditions, using 25 wt.% glucose solution for the industrial agriculture applications. The heat treatment process was carried out for one hour at 900 ± 10 °C, followed by quenching with monograde motor oil and tempering for more than two hours at 200 ± 10 °C. Several analyses were conducted to estimate the final mechanical, surface morphological and tribological properties for the studied materials, before and after the heat treatment process. The heat-treated martensitic stainless steel grade exhibited superior wear resistance and higher hydrophobicity compared to the other two heat-treated austenite stainless steel grades. Therefore, the mechanism of the heat treatment process, the chemical and physical nature of the parent material, and the viscosity of the selected lubricant all influence the final behaviour of the studied material against the applied operating conditions for the selected application.