Machine Learning-RSM Hybridized Evaluation of the Kinetics and Thermodynamics of Mild Steel Corrosion Inhibition Using Lagenaria Breviflora Extract

The inhibition of mild steel corrosion in dilute hydrochloric acid (1 M HCl) by the xylene extract of Lagenaria breviflora (XEL-B) was studied using a Central Composite Design (CCD) structured Response Surface Methodology (RSM). A statistically optimised 20-run experimental matrix was employed to evaluate the simultaneous effects of inhibitor concentration, immersion time and temperature on mass loss, corrosion rate (Rc), inhibitor efficiency (IE), and surface coverage (θ). The fitted quadratic response surface model was highly significant (F = 55.81, p < 0.0001) with a non-significant lack of fit (p = 0.2730), confirming adequate model predictability across the experimental domain. Inhibitor efficiency ranged from 28.68% at 31 ppm of inhibitor concentration to 77.01% at 368 ppm, with inhibitor concentration identified as the dominant process variable statistically validated (F = 423.40, p < 0.0001) cosnsistent with 4D response surface analysis, and a 500-tree Random Forest ensemble machine learning model (factor importance: IE = 77.54%, Rc = 74.20%). Adsorption of XEL-B on mild steel conformed to the Langmuir monolayer isotherm (R² = 0.9950), equilibrium adsorption constant K_ads of 11.3649Lg⁻¹ and standard Gibbs free energy of adsorption ΔG°ads of −16.24 kJ/mol, confirming spontaneous, thermodynamically favourable adsorption with a mixed physisorptive–chemisorptive mechanism. These integrated experimental-computational results established XEL-B as a potential green corrosion inhibitor for mild steel in dilute acidic environments relevant to oilfield and industrial acid-treatment operations.

Lagenaria breviflora; corrosion inhibition; steel; RSM; Langmuir isotherm; Random Forest; machine learning

1. Adesina, O. S., Ogundipe, O. B., Ajewole, J. B., Sanyaolu, O. O., Durugbol, J., Adekanye, T. A., Olabanji, T. S., Alao, O. P., & Dada, T. J. 2025. Corrosion Challenges, Monitoring Techniques, and Mitigation Strategies in The Oil and Gas Industry: A Critical Review. Journal of Science and Technology Research,7, pp. 267–278. [Google Scholar] [Crossref]

2. Alamiery, A. A., Isahak, W. N. R. W., Aljibori, H. S. S., Al-Asadi, H. A., & Kadhum, A. A. H. (2021). Effect of the structure, immersion time and temperature on the corrosion inhibition of 4-pyrrol-1-yl-N-(2,5-dimethyl-pyrrol-1-yl)benzoylamine in 1.0 M HCl solution. International Journal of Corrosion and Scale Inhibition, 10(2), 700–713. https://doi.org/10.17675/2305-6894-2021-10-2-14 [Google Scholar] [Crossref]

3. Alao, A. O., Popoola, A. P., Dada, M. O., & Sanni, O. (2022). Utilization of green inhibitors as a sustainable corrosion control method for steel in petrochemical industries: A review. Frontiers in Energy Research, 10, Article 1063315. https://doi.org/10.3389/fenrg.2022.1063315 [Google Scholar] [Crossref]

4. Al Otaibi, N., & Hammud, H. H. (2021). Corrosion inhibition using Harmal leaf extract as an eco-friendly corrosion inhibitor. Molecules, 26(22), 7024. https://doi.org/10.3390/molecules26227024 [Google Scholar] [Crossref]

5. Al-Baghdadi, S., Gaaz, T. S., Al-Adili, A., Al-Amiery, A. A., & Takriff, M. S. (2021). Experimental studies on corrosion inhibition performance of acetylthiophene thiosemicarbazone for mild steel in HCl complemented with DFT investigation. International Journal of Low-Carbon Technologies, 16(1), 181–188. https://doi.org/10.1093/ijlct/ctaa050 [Google Scholar] [Crossref]

6. Bandeira, R. M., Lima, F. P., Nunes, M. S., dos Santos, E. C., dos Santos Júnior, J. R., de Matos, J. M. E., Feitosa, C. M., Rai, M., Bhattarai, S., & Das Mulmi, D. (2025). The green plant-based corrosion inhibitors—a sustainable strategy for corrosion protection. Surface Science and Technology, 3, Article 19.https://doi.org/10.1007/s44251-025-00019-x [Google Scholar] [Crossref]

7. Barbu, C. A., Fierascu, I., Semenescu, A., & Cotrut, C. M. (2025). Critical Review Regarding the Application of Plant Extracts as Eco-Friendly Corrosion Inhibitors—A Sustainable Interdisciplinary Approach. Molecules, 30(18). https://doi.org/10.3390/molecules30183722 [Google Scholar] [Crossref]

8. Cappelli, F., Castronuovo, G., Grimaldi, S., & Telesca, V. (2024). Random Forest and Feature Importance Measures for Discriminating the Most Influential Environmental Factors in Predicting Cardiovascular and Respiratory Diseases. International Journal of Environmental Research and Public Health, 21(7), 867. https://doi.org/10.3390/ijerph21070867 [Google Scholar] [Crossref]

9. Iroha, N.B., Akaranta, O. Experimental and surface morphological study of corrosion inhibition of N80 carbon steel in HCl stimulated acidizing solution using gum exudate from Terminalia Mentaly, 2020. SN Applied Sciences, 2(1514). https://doi.org/10.1007/s42452-020-03296-8 [Google Scholar] [Crossref]

10. Ituen, E., Singh, A., Yuanhua, L., & Akaranta, O. (2021). Biomass-mediated synthesis of silver nanoparticles composite and application as green corrosion inhibitor in oilfield acidic cleaning fluid. Cleaner Engineering and Technology, 3, 100119. https://doi.org/10.1016/j.clet.2021.100119 [Google Scholar] [Crossref]

11. Kania, H., 2023. Corrosion and Anticorrosion of Alloys/Metals: The Important Global Issue. Coatings, 13(2), https://doi.org/10.3390/coatings13020216 [Google Scholar] [Crossref]

12. Kumari, P., & Lavanya, M. (2022). Plant extracts as corrosion inhibitors for aluminum alloy in NaCl environment - Recent review. Journal of the Chilean Chemical Society, 67(2). https://doi.org/10.4067/S0717-97072022000205490 [Google Scholar] [Crossref]

13. Mohammad, A. & Jafar, M., 2020. Global Impact of Corrosion: Occurrence, Cost and Mitigation. Global Journal of Engineering Science. 5(4): https://doi.org/10.33552/GJES.2020.05.000618 [Google Scholar] [Crossref]

14. Yuan, X., Liu, S., Feng, W. & Dauphin, G., 2023, Feature Importance Ranking of Random Forest-Based End-to-End Learning Algorithm. Remote Sensing, 15, 5203. https://doi.org/10.3390/rs15215203 [Google Scholar] [Crossref]

15. Zakeri, A., Bahmani, E., & Sabour Rouh Aghdam, A. (2022). Plant extracts as sustainable and green corrosion inhibitors for protection of ferrous metals in corrosive media: A mini review. Corrosion Communications, 5, 25–38. https://doi.org/10.1016/j.corcom.2022.03.002 [Google Scholar] [Crossref]

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