Corrosion Inhibition Of Mild Steel Research Articles

Assessment of the Inhibitory Efficacy of a Thiazole Derivative as an Efficient Corrosion Inhibitor for Augmenting the Resistance of MS in Acidic Environments.

Numerous thiazole compounds have been developed as cutting-edge inhibitors because of a rising fascination with using corrosion inhibitors (CIs) and preventative measures to prevent mild steel (MS) from deteriorating. In this study, the ability of a novel thiazole derivative, 2-hydrazono-3-methyl-2,3-dihydrobenzo[d]thiazole hydrochloride (HMDBT), to prevent corrosion of MS (MS) in HCl has been reconnoitered using various approaches, Viz. gravimetric analysis, electrochemical (EC) analysis, and different surface characterizations. With an inhibition efficiency (IE %) of 95.35%, the outcomes elucidate that HMDBT functions as a potent MS CI that is environmentally friendly and sustainable. The computed activation and thermodynamic factors were also employed to better explain the process underpinning the inhibiting tendency of HMDBT. According to the computed values, the HMDBT molecules physically and chemically adhered to the MS surface following the Langmuir model, generating a dense protective layer that may be associated with the presence of a benzene ring and heteroatoms (S & N) in the HMDBT architecture. Based on the findings of the EIS studies, an intensification in the CI's concentration from (50 →800) ppm is ushered by increases in polarization resistance (Rp) from (80.72, 354.31) Ω cm2, and attenuation in double-layer capacitance (Cdl) from (198.78 → 44.13) μF cm-2, respectively, confirming the inhibitory proficiency of HMDBT. The IE of the inhibitor was reported around 95.35% by weight loss measurement and 89.94% through EC measurement. Theoretical analysis including density functional theory (DFT) and molecular dynamics (MD) simulations were carried out to investigate the additional effects of HMDBT on the anticorrosion effectiveness and mechanism of inhibition. The theoretical parameters that were calculated provided important assistance in comprehending the inhibitory mechanism that the CI's moieties disclosed and are in strong concord with experimental methods. To create a "green" inhibitor system, the work presented here provided a potent technique to reduce corrosion by adding a potent new inhibitor.

Lawsonia inermis as an Active Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

Corrosion is a pervasive issue affecting metallic materials, with significant economic losses and safety risks in various industries. Mild steel, extensively used in construction and infrastructure, faces corrosion challenges, needing continuous research to effectively tackle them. Natural compounds, because of their eco-friendliness and corrosion inhibition potential, are attracting increasing interest for corrosion control. Lawsonia inermis (LI), or henna, a plant native to North Africa and South Asia, has bioactive compounds exhibiting corrosion inhibitive properties. This study comprehensively explores Lawsonia inermis’s effectiveness as a corrosion inhibitor for mild steel, filling a gap in the existing research. Various concentrations of Lawsonia inermis extract were tested in acidic solutions to evaluate corrosion inhibition. Experimental results indicate a significant reduction in the corrosion rate with increasing inhibitor concentration. Langmuir adsorption isothermal analyses reveal the adsorption mechanism as being an interplay between physisorption and weak chemisorption. Electrochemical measurements demonstrate Lawsonia inermis’s capability to alter both cathodic and anodic reactions, leading to improved corrosion resistance. Scanning electron microscopy reveals a more even surface morphology in the presence of the Lawsonia inermis, indicating corrosion inhibition. Gas chromatography–mass spectrometry (GC-MS) analyses identified organic compounds in Lawsonia inermis extract responsible for corrosion inhibition. Overall, Lawsonia inermis emerges as a promising corrosion inhibitor for mild steel, offering excellent inhibition efficiencies. This study sheds light on its adsorption behaviour and provides insights into its mechanism of action. These findings underscore Lawsonia inermis’s potential as a green corrosion inhibitor, paving the way for its practical application in industrial corrosion protection strategies.

Alkaloid extract of seed Citrullus colocynthis as novel green inhibitor for mild steel corrosion in one molar HCl acid solution: DFT and MC/MD approaches

The study was designed to explore the corrosion prevention capabilities of Citrullus colocynthis seeds alkaloid-rich extract (CSEA) on MS in a 1 M HCl environment by use of electrochemical and theoretical methods. Notably, Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization were used to probe the impact of immersion time and temperature. Energy-dispersive X-ray spectroscopy (EDX) and spanning electron microscopy (SEM) were used to confirm the presence of a protective layer on the substrate surface. Density functional theory (DFT) method was used to optimize the investigated species by use of B3LYP/6–31 + G(d, p) level of theory. The global and local quantum chemical reactivity descriptors were calculated to explore the inhibition corrosion efficiency and to identify the most favorable sites for electrophilic and nucleophilic attacks. Monte Carlo (MC) and molecular dynamics simulation (MDS) methods were used to study the interactions between corrosion inhibitor and metal surface. Noteworthy, results showed that CSEA exhibited an impressive inhibition efficiency, which reached 94.3% with a concentration of 2 g/L at 298 K. Potentiodynamic polarization revealed that the extract acted as a mixed-type inhibitor. Nyquist graphs showed that charge-transfer resistance and dæouble-layer capacitance both rised with increasing CSEA concentration, suggesting better inhibition efficiency. Notably, the Langmuir adsorption isotherm is well-aligned with the adsorption of inhibitor compounds. Importantly, all aforementioned theoretical methods were in agreement with the experimental findings. The outcome of the present work supported using Citrullus colocynthis seeds alkaloid-rich extract as ecofriendly agents to prevent corrosion.

Investigating the efficacy of phenolic Schiff bases as corrosion inhibitors for mild steel in acidic environments: Integrating experimental and theoretical approaches (Part B)

Our research employs a holistic methodology to assess the efficacy of a series of phenolic Schiff bases as corrosion inhibitors for mild steel in a 1 M HCl solution. Through complementary studies, we aim to unravel the corrosion inhibition mechanism by investigating neutral, protonated, and complex forms of inhibitors using advanced computational and statistical methods. This initial investigation specifically involves evaluating the effectiveness of two phenolic Schiff bases through weight loss tests (WL) and electrochemical techniques. The study focuses on the corrosion inhibitory properties of two phenolic Schiff bases, namely 4,4′-((1E,1′E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))diphenol (PSB7) and (1E,1′E)-N,N'-(ethane-1,2-diyl)bis(1-(4-nitrophenyl)methanimine) (PSB8), on mild steel (MS). Results from weight loss and electrochemical methods indicate that inhibition efficiency improves with decreasing temperature and increasing inhibitor concentration, reaching 94 % (for PSB7) and 93 % (for PSB8) at 303 K and 1 × 10−3 M, respectively. Consequently, both PSB7 and PSB8 function effectively as inhibitors in a mixed form. The adherence of both inhibitors to the surface follows the Langmuir adsorption isotherm model. Additionally, SEM and EDS experiments provide evidence of adsorption on the surface. The findings from Density Functional Theory (DFT) and Molecular Dynamic Simulations (MDS) consistently match the actual data, maintaining the order of inhibition efficiency (PSB7 > PSB8).

Combined electrochemical, surface analysis and DFT/MD-simulations to evaluate choline histidine ionic liquid as a green corrosion inhibitor for mild steel in neutral medium

The current research reports the performance of choline histidine ionic liquids ([Ch][His]) as novel corrosion inhibitor for mild steel in 3.5 wt% NaCl solution. According to the experimental findings, [Ch][His] significantly inhibit the mild steel corrosion. The inhibition efficiency is positively correlated with the inhibitor concentration and negatively correlated with the temperature. Optimal inhibition efficiency was 89.8 %, 86.9 % and 84.0 % for weight-loss analysis, polarization test (PDP) and electrochemical impedance (EIS) at 3000 ppm. The surface analysis visualized that the surface of mild steel was less corroded and damaged in the solution containing [Ch][His] compared to the blank solution. The [Ch][His] showed the anodic type of mild steel corrosion inhibition with both chemisorption and physisorption nature following Langmuir adsorption isotherms. MD simulation and Quantum chemical calculation evidenced that [Ch][His] forms a barrier film on the mild steel surface, confirming the experimental results.

Phytochemicals as eco-friendly corrosion inhibitors for mild steel in sulfuric acid solutions: a review

Abstract Plant extracts represent abundant sources of biomolecules distributed throughout various plant parts. These biomolecules are extracted using diverse solvents and methods. Within these plant extracts lie bioactive compounds, known for their antioxidant properties and anticorrosive capabilities. Detecting and isolating these active biomolecules from plant extracts necessitates analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. The active biomolecules within plant extracts contain heteroatoms within their structures, facilitating their adsorption on steel surfaces and conferring corrosion inhibition properties. The advantages of plant extracts as green corrosion inhibitors include ready availability, ease of application, eco-friendly characteristics, and cost-effectiveness. These extracts adhere to steel surfaces, blocking their active sites and effectively reducing the corrosion rate. This review consolidates the findings on the corrosion inhibition potential of plant extracts from various plant parts, elucidating their performance in different concentrations of sulfuric acid.

Performance Evaluation of Bryophyllum Pinnatum Leaves Extract as Corrosion Inhibitor for Mild Steel in 1 M Phosphoric Acid

Performance Evaluation of Bryophyllum Pinnatum Leaves Extract as Corrosion Inhibitor for Mild Steel in 1 M Phosphoric Acid

Experimental and Theoretical Investigation of the Inhibitor Efficiency of Eucalyptus globulus Leaf Essential Oil (EuEO) on Mild Steel Corrosion in a Molar Hydrochloric Acid Medium.

As a corrosion inhibitor for mild steel in a molar hydrochloric acid medium, we investigated the potential of Eucalyptus globulus essential oil (EuEO). Through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves, and theoretical methods, including DFT/B3LYP 6-31G (d, p) and Monte Carlo simulations, the interactions between the EuEO components and the steel surface were analyzed. D-Allose, Betulinaldehyde, and Uvaol were identified as the major active compounds in the GC-MS analysis. The experimental results showed that EuEO reached an inhibitory efficiency as high as 97% at a 1 g/L concentration. The findings suggest that EuEO operates as a mixed-type inhibitor, reducing both cathodic and anodic reactions, as well as building up a protective coating on the steel surface. Simulations also confirmed that EuEO molecules function as electron donors and acceptors, enhancing corrosion resistance.

Development of a 2D Network of Zinc Organophosphate with an 8-Membered Ring Core Having Corrosion Resistance Properties.

A 2D framework, i.e., zinc organophosphate [Zn(tmbiph)(solv)]2 (tmbiphH4 = tetramethyl-[1,1'-biphenyl]-4,4'-diyl bis(dihydrogen phosphate); solv = 2H2O) with an eight-membered ring core has been developed. The hierarchical and rational design of the zinc organophosphate has been achieved by carefully designing an organic bisphosphate ligand with two phosphate monoester groups connected through extended aromatic rings with methyl groups at ortho positions. The development of the 2D network does not require any ancillary ligand due to participating two phosphate groups in the coordination. The molecular structure of the zinc phosphate material was determined using single-crystal X-ray diffraction technique. The corresponding Co and Cu organophosphate materials have also been obtained using the same synthetic method; however, these compounds could not be confirmed structurally due to nondiffractive crystal quality. The structure of zinc organophosphate obtained through single-crystal X-ray diffraction has also been supported by theoretical calculations using density function theory. Furthermore, the zinc organophosphate material has been employed as an corrosion inhibitor for mild steel. The effect of the zinc phosphate framework on mild steel in 1 M HCl was investigated using polarization and electrochemical impedance spectroscopy. This study suggests that such phosphate inhibitors can be employed in the form of a thin protective layer on the electrode surface.

Acid corrosion inhibition of mild steel by 8-hydroxyquinoline derivatives: organic synthesis, characterization, chemical, electrochemical investigation and theoretical calculations

In this study, two 8-hydroxyquinoline derivatives, HAPAQ and EAPAQ, were first synthesized, and their molecular structures were confirmed by 1H and 13C NMR. The effects of HAPAQ and EAPAQ on corrosion processes were investigated using weight loss, electrochemical, and theoretical methods. Overall, the data unmistakably demonstrate that the inhibition performance (η %) increases with an increase as HAPAQ and EAPAQ concentrations rise, peaking at 96.08% (HAPAQ) and 94.37% (EAPAQ) at the optimal concentration (10−3 M) for PPD technology. The two 8-hydroxyquinoline derivatives exhibit inhibitory behavior, as seen by the polarization curve impedance tests; however, they demonstrate that adsorption promotes protective action on metal surfaces, creating a geometric blocking effect and a protective coating that impedes metal breakdown. HAPAQ and EAPAQ's inhibitory efficacy may be reduced by the rising temperature. Furthermore, it adheres to Langmuir’s single-layer adsorption isotherm, and the physisorption and chemisorption mechanisms are linked to the corresponding value of the adsorption energy (ΔG ads). Additionally, the MS scanning electron microscope (SEM) has been studied and discussed. The possibility of complex organization between the inhibitor molecules, 8-hydroxyquinoline derivatives (HAPAQ and HAPAQ), and the Fe2+ ions generated during the oxidation process was established by examining the test solutions using UV–visible spectroscopy. Consequently, it is evident from DFT simulations that the surface recovery is dependent on the local reactivity descriptors. The theoretical outcomes derived from DFT are aligned with the findings of the experimental studies.

The use of amines as steel corrosion inhibitors in butanol-gasoline blends

Butanol is an interesting component used for blending gasoline fuels. However, the polar nature of butanol allows the solubility of water and ionic compounds in butanol-gasoline blends (BGBs) making them aggressive to mild steel. Amines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentaamine, morpholine, piperazine, and hexamethylenediamine, were tested as corrosion inhibitors for mild steel in BGBs. Additionally, the influence of the acetic acid and sodium chloride concentrations on the inhibition efficiency was examined. Electrochemical impedance spectroscopy andpotentiodynamic polarization were employed for the measurements, complemented by static immersion testing and an XPS surface analysis. The highest inhibition efficiency was demonstrated for diethylenetriamine, triethylenetetramine, andhexamethylenediamine, achieving a value of 95 % or more at aconcentration of 100 mg/L. The formation of ionic pairs involving protonated amines andchlorides was also confirmed. The XPS analysis revealed a very thin passive layer of iron oxides, which may form in the presence of amines, protecting mild steel in BGBs.

Zea mays bracts extract as an eco-friendly corrosion inhibitor for steel in HCl pickling solution: Experimental and simulation studies

Active phytochemicals with unique electron structures can adsorb on metal surfaces and effectively mitigate metal corrosion. Recently, plant extracts have garnered significant attention as green and renewable corrosion inhibitors. In this study, the abundant agricultural byproducts, namely Zea mays bracts, were used as the extract raw materials, and Zea mays bracts extract (ZMBE) was served as an eco-friendly corrosion inhibitor for mild steel (MS) in 1 M HCl pickling solution. The organic substances in ZMBE were analyzed via ultra-high performance liquid chromatography- quadrupole time-of-flight mass spectrometry (UPLC-QTFMS). The interaction between the active functional groups and MS was investigated using Fourier transform infrared (FT-IR) and ultraviolet–visible (UV–visible) spectroscopy and X-ray photoelectron spectroscopy (XPS). The corrosion inhibition behavior was scrutinized through potentiodynamic polarization (PDP) curves and electrochemical impedance spectroscopy (EIS). The results show that functional groups such as aromatic rings, double bonds, and hydroxyls successfully adsorb on the MS surface to form the protective films. ZMBE exhibits a mixed-type corrosion inhibition with a “geometric coverage” effect. The corrosion inhibition efficiency (η) increases with ZMBE concentration and solution temperature, the optimum η with 5.0 g·L−1 ZMBE at 318 K is 96.2 %. The adsorption of active ingredients follows the Langmuir and El-Awady isotherms. Density functional theory (DFT) and molecular dynamics (MD) simulations prove the synergistic effect of complex components in ZMBE and the corrosion inhibition mechanism. ZMBE is a promising acid pickling corrosion inhibitor with broad application prospects.

Experimental accompanied with computational (atomic/electronic)-level simulation investigations of Polygonum cuspidatum root extract as sustainable corrosion inhibitor for mild steel in aggressive corrosive media.

This study investigates the corrosion inhibition potential of Polygonum cuspidatum root extract (PCRE) on mild steel in a 0.5M HCl acidic environment. Herein, various techniques including electrochemical and gravimetric measurements were employed, along with scanning electron microscopy (SEM) and contact angle (CA) measurements for surface morphology analysis. The impedance study revealed a concentration-dependent enhancement in corrosion resistance, classifying PCRE as a mixed-type inhibitor (i.e., inhibits both anodic and cathodic reactions). The highest efficiency, 96.71% at 298K, was observed at a 1000-ppm PCRE concentration. Langmuir model computations suggested chemisorption and physisorption of PCRE on the electrode substrate. Increased Rp (from 28.648 to 174.01 Ω) and Rct (185.74 Ω cm2) at 1000ppm demonstrated improved corrosion resistance. Additionally, SEM analysis displayed a uniform, protective surface, reducing metal degradation. Theoretical calculations highlighted strong interactions between PCRE and mild steel, with a low energy gap (ΔE), as follows: 1-O-methylemodin (2.267eV) < emodin (2.288eV) < emodin-1-O-glucoside (2.343eV) < piceid (2.931eV) < resveratrol (2.952eV), confirming PCRE's excellent micro-level anti-corrosion capabilities. This eco-benign corrosion inhibitor offers sustainable, low-toxicity protection, cost-effectiveness, and versatile performance, surpassing commercial counterparts while aligning with sustainability goals.

Investigation of mild steel corrosion inhibition in acidic media by Viola extract based on bulk and nanometer size

In the present work, the inhibition performance of Viola extract based on bulk and nano size as a green corrosion inhibitor on mild steel in 0.5 M phosphoric acid and 1M hydrochloric acid solutions is investigated using different techniques (potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and Optical microscopy). The gained results demonstrated that various concentrations of Viola Extract (bulk and nano) inhibited the corrosion of the alloy in both of the acid solutions. The temperature impact on corrosion rate without/with this extract was examined. Certain thermodynamic parameters were determined based on the temperature impact on inhibition and corrosion processes. The adsorption mechanism of the extract on the alloy was explored using the Langmuir adsorption isotherm. A mixed mode of adsorption was observed, wherein the nano-sized extract in 1.0 M HCl predominantly underwent chemisorption, while the bulk-sized extract in 1.0 M HCl and both bulk and nano-sized extracts in 0.5 M H3PO4 were primarily subjected to physisorption. Scanning electron microscopy (SEM) and Optical microscopy analyses were employed to scrutinize alloys’ surface morphology.

Experimental, theoretical and computational studies of oxalyl dihydrazide as a novel corrosion inhibitor for mild steel in neutral saline solution

In this work, the corrosion inhibition performance and mechanism of oxalyl dihydrazide (ODH) for mild steel in neutral saline solution are in-depth studied using weight-loss and electrochemical tests, surface characterizations, theoretical calculation and computational simulations. Results indicate that ODH can act as a novel and superior mixed-type corrosion inhibitor for mild steel in neutral saline solution, its corrosion inhibition efficiency increases with the rising ODH concentration, and the optimum value reaches 88.7 % with adding 200 mg/L. Its corrosion inhibition ability becomes better with immersion time. A compact corrosion product film mainly consisting of Fe, O, N and Cl elements formed on metal surface after adding ODH. ODH molecules adsorb on metal surface in an orderly fashion to form a hydrophobic film, which is belonging to the physicochemical adsorption and obeys the Langmuir adsorption isotherm model. The corrosion inhibition process of ODH molecule on mild steel is the endothermic process, which enlarges the activation energy barrier of corrosion reactions. ODH molecule can expel the adsorbed water molecules on metal surface and form copolymers with increasing of ODH concentration, retarding the diffusion of water molecule thus protecting metal from corrosion. ODH is proved to be an effective organic corrosion inhibitor for protecting mild steel in neutral saline solution, and contributes toward research and application of easily accessible sources for organic corrosion inhibitors.

Valorisation of leather buffing dust as corrosion inhibitor for mild steel in H2SO4 acid

This work discusses the valorisation and efficacy of the acid-extracted collagenous proteins from leather buffing dust (LBD) on the corrosion inhibition of mild steel (MS) in 0.5 M H2SO4 solution using electrochemical analysis. The extract shows ~95 % inhibition efficiency at 1 wt% of raw LBD loading. The inhibitor interaction follows Langmuir adsorption isotherm, indicating monolayer adsorption through physisorption, leading to complex formation on the MS surface. Post-corrosion characterizations reveal film-forming nature of the inhibitor and the involvement of organic compounds in the complex protective layer formation on the MS in the corrosive media. In addition, surface study through an optical profilometer helps to understand the nature of the corroded MS. In summary, the LBD-H2SO4 extract is extremely capable in mitigating the corrosion of MS in H2SO4 solution, and the inhibition phenomenon is governed by a complex passive layer formation on the MS subjected to the corrosive media.

Versatility of Juçara (Euterpe edulis) extracts as corrosion inhibitors of mild steel in different environments: 1 mol L−1HCl and CO2-saturated formation water

Versatility of Juçara (Euterpe edulis) extracts as corrosion inhibitors of mild steel in different environments: 1 mol L−1HCl and CO2-saturated formation water

Effectiveness of Expired Estradiol Valerate Drug Molecule as a Corrosion Inhibitor for Mild Steel in 1 M HCl Medium: Waste Utilization Perspective

This study explores the utilization of expired pharmaceutical drugs, specifically Progynova 2 mg (estradiol valerate), as a sustainable solution for corrosion inhibition in mild steel exposed to a 1 M HCl medium at 30°C. Through a comprehensive analysis employing FTIR, mass loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), quantum chemical analysis (DFT), and scanning electron microscope (SEM), the research confirms the remarkable effectiveness of estradiol valerate (EPROG) in inhibiting mild steel corrosion, achieving an impressive 94.27% inhibition efficiency at a concentration of 600 ppm. Potentiodynamic polarization reveals mixed-type inhibition behavior, while EIS measurements indicate increased charge transfer resistance (Rct) and reduced double layer capacity (Cdl) with higher estradiol valerate concentrations, in line with Langmuir adsorption isotherm results. The DFT analysis of the EPROG inhibitor indicates that it use a donor-acceptor mechanism to interact with the metal surface. SEM analysis further substantiates the presence of a stable EPROG inhibitor layer on the mild steel surface, underscoring its corrosion inhibition properties and advocating for the sustainable repurposing of expired pharmaceuticals in environmental and structural preservation efforts.

Excellent corrosion inhibition efficiency of Catharanthus roseus (Nayantara or Sadabahar) leaf aqueous extract on mild steel in chloride-contaminated solutions at different pH

The efficacy of Catharanthus roseus (Nayantara) leaf extract as a green corrosion inhibitor for mild steel in chloride-contaminated environments has been investigated in the present work. This study has employed a straightforward, practical, and less expensive Maceration process to prepare leaf extract. The adaptability of the extract as a corrosion inhibitor has been evaluated through electrochemical polarization and impedance studies in chloride-contaminated environments with varying pH levels. In addition, long-term corrosion monitoring has been conducted to evaluate the sustainability of the inhibitor against chloride-induced corrosion at a neutral pH level. This novel study has revealed that the extract defends mild steel against chloride assaults better at pH 2 than it does in neutral or alkaline conditions. Moreover, electrochemical studies and subsequent characterizations have confirmed the film-forming nature of the inhibitor.

Investigation of Garcinia kola Exudates as Corrosion Inhibitor for Mild Steel in Acidic Environment

This study investigated the performance of Garcinia kola exudates in preventing mild steel exposed to acid concentrated water and soil. The study was performed in order to find an alternative coating substance that can reduce the corrosion of mild steel pipes exposed to corrosive water and soil media. Various mild steel specimens were cut into portions and coated with the exudates at 25 - 50µm thickness. To accelerate the rate of corrosion, 0.5M hydrochloric acid (HCl) was added to tap water in a container. Also, the same concentration of HCl was equally added to soil samples. Uncoated mild steel specimens were immersed in the acid concentrated water and soil, servicing as control sample. The rate of corrosion was monitored for 30 days (720 hours). The inhibition efficiency of the exudates for both corrosive media was compared. Results showed that the weight loss and corrosion rate of mild steel decreased with increase in coating thickness. Comparatively, weight loss and corrosion rate in the uncoated specimens were higher than the coated specimens. For uncoated specimens, the corrosion rate was 0.2793mm/yr and 0.4150mm/yr for specimen immersed in water and soil respectively, but at 25µm coating thickness, it decreased to 0.01369mm/yr and 0.2870mm/yr for specimens in water and soil. Also, at 50µm coating thickness, corrosion rate decreased to 0.0052mm/yr and 0.0318mm/yr for specimens in water and soil, respectively. The inhibition efficiency increased with coating thickness, ranging from 51.00 – 98.15% for specimens immersed in water and 30.84 – 92.33% for specimens buried in soil at 25µm – 50µm coating thickness. The results demonstrated that Garcinia kola exudates can be used as corrosion inhibitor for mild steel exposed to corrosive media.