Corrosion In Presence Research Articles

Corrosion behavior of AA5052 aluminum alloy in the presence of heavy metal ions in 3.5 % NaCl solution under negative pressure

Aluminum alloy heat exchange tube is attractive for the Low Temperature-Multi Effect Distillation (LT-MED) desalination device, for its low cost and excellent mechanical property. However, it is prone to galvanic coupling corrosion in presence of heavy metal ions. In this paper, the effect of Cu2+ and Fe3+ ions on the corrosion of aluminum alloy in 3.5 wt% NaCl solution under negative pressure is investigated by the weight-loss method and the electrochemical measurements. It shows that the operation pressure affects significantly the corrosion behavior of AA5052 aluminum alloy in presence of heavy metal ions. As the pressure decreases, the resistance of the aluminum alloy to corrosion increases markedly. The corrosion products formed under different operation pressure are detected by SEM, XRD analysis. It is found that the diffusion process of corrosion products from the aluminum alloy surface into the solution is prevented as the decrease of pressure, resulting in the formation of the passivation layer on the aluminum alloy surface. The decrease of pressure can effectively restrain the heavy metal ions to be adsorbed on the defects of the oxide layer and mitigate the corrosion of aluminum during the LT-MED desalination process.

Corrosion inhibition using guar gum grafted 2-acrylamido-2-methylpropanesulfonic acid (GG-AMPS) in tubular steel joints

The ability of Guar Gum grafted 2-Acrylamido-2-Methylpropanesulfonic Acid (GG-AMPS) to mitigate the corrosion of carbon steel in ASTM standard D1141-98(2013) artificial seawater was examined using gravimetric (mass loss), theoretical simulations, electrochemical, and surface analysis techniques. Gravimetric method suggested the mitigation of corrosion in presence of GG-AMPS. Simulations were done using ABAQUS software on tubular TT-joints, which showed higher reduction in its ultimate capacity once the thickness was reduced due to corrosion. Impedance experiments emphasized the rise in charge transfer resistance with higher GG-AMPS concentration. The polarization results revealed that GG-AMPS showed cathodic predominance. Scanning electrochemical microscopy (SECM), method was used to determine the localized corrosion activity. Scanning Electron Microscopy (SEM) analysis revealed the GG-AMPS film formation.

Comparison of microbial influenced corrosion in presence of iron oxidizing bacteria (strains DASEWM1 and DASEWM2)

Microbial influenced corrosion (MIC) is one of the major concerns in industries due to huge economic losses. Sulfate-reducing bacteria (SRB) are well studied and highly corrosive in nature. However, the MIC mechanism, especially by iron-oxidizing bacteria (IOB) is not yet elucidated. In this context, this study presented the co-relation of extra polymeric substances (EPS) exuded by IOB strains as a key mechanism for MIC of mild steel. Herein, the corrosion behavior of mild steel influenced by EPS of two IOB strains; DASEWM1 and DASEWM2 isolated from river water was investigated. Comparative studies using surface analysis, electrochemical tests and immersion tests in nutrient broth media revealed a higher degree of corrosion in inoculated media (strain DASEWM1 < DASEWM2) than control media. These results were also supported by EIS and FESEM of corroded steel surfaces. Moreover, electrochemical and EPS constituent’s analysis, the correlation between the corrosion rate to the EPS constituents were also studied.

G EFFECT OF VIBRATION-CORROSION ON ALUMINUM ALLOY(DIN1100) THAT WELDED BY TIG TECHNIQUE AND OPERATING IN THE MARINE ENVIRONMENT

In this research studied the effect of corrosion in presence of vibration on aluminum alloy type (DIN1100) operating in sea water (3.5% NaCl) and compared these results with the same alloy after it was welded by TIG technique at the same vibrated corrosive medium, addition to study the corrosion in static medium for welded and non- welded alloy, then comparison between the four cases depending on corrosion rates and microstructures it was noted that ;the greatest percentage of corrosion rate was 43% of welded alloy at vibration-corrosion and least percentage of corrosion rate was 8% of non-welded alloy at static corrosion.&#x0D;

In situ surface film evolution during Mg aqueous corrosion in presence of selected carboxylates

Mechanisms of inhibition of Mg aqueous corrosion in presence of chloride by sodium salicylate (Sal), 2,5-pyridinedicarboxylate (PDC) and fumarate (Fum) were studied by in situ Raman spectroscopy, ATR-FTIR, GD-OES and hydrogen collection. In situ detected surface films were composed by Mg(OH)2 nano-crystals and included inhibitors. All carboxylates significantly modified Mg(OH)2 growth kinetics as well as pevented chloride incorporation in the film. Vibrational spectra of the surface films demonstrated specific interactions between the carboxylates and the surface: adsorption of Sal and Fum on the oxide/hydroxide, precipitation of coordination polymer by PDC, dissolution of iron inclusions via formation of iron-Sal soluble complexes.

A New Insight into Non‐Steroidal Anti‐Inflammatory Drugs (NSAIDs) as Modulated Green Inhibitory Agent on Mild Steel Corrosion

AbstractPresent study investigate the corrosion inhibition action of green non‐steroidal anti‐inflammatory drugs (NSAIDs) on mild steel (MS) in 1 M HCl by Gravimetric method, Electrochemical Impedance Spectroscopy and Potentiodynamic Tafel polarization at 303.15 K. Changes occurring in the impedance parameters (Rct and Cdl) give clear indication of drug adsorption on the metal surface. Polarization study inferred these drugs to act as a mixed inhibitor. Experimental results inferred a rise in inhibition efficiency with increasing drug concentration. i. e. 90%, 71% and 85% for Aspirin (∼0.3 mM), Diclofenac (∼0.1 mM) and Ibuprofen (∼0.7 mM) respectively. The formation of the Fe‐inhibitor complex and the corrosion inhibition mechanism was inferred by spectral study. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) gave evidences of the surface topography and proved that the metal surface resist corrosion in presence of inhibitor than in its absence. The degree of hydrophobicity induced due to drug adsorption as obtained by contact angle (CA) is in good agreement with the microscopic results which inferred NSAIDs to act as an effective inhibitor in acidic corrodent. Thermodynamic study confirmed the adsorption process to be spontaneous i. e., ΔG̊ads lies between −17.0 to −20.0 kJ mol−1 which obeyed the Langmuir isotherm. A successive correlation of NSAIDs with their calculated molecular orbital energy levels is well explained using simulation by Density Functional Theory.

Comparative Study of Chloride and Fluoride Induced Al Pad Corrosion in Wire Bonded Packaging Assembly

Microelectronics are used in virtually all electronic equipment’s nowadays ranging from medical instruments, automobiles, computers, cell phones and home appliances. Wirebonding process which connects the chip to the lead frame in IC packaging plays a very important role in the commercial production of IC’s. Chip usually consists of Al bond pads with Cu/Au wires. Thin film Al bond pads are easily vulnerable to corrosion in presence of contaminants and moisture. Bond pad corrosion is one of the common modes of corrosion failure in wire-bonded devices IC packaging. Improper rinsing, packaging and passivation defects allows moisture and contaminants into bondpads resulting in severe corrosion. Most common source of this corrosion comes from the presence of halide ions contamination as (Cl-, F-, Br- etc.) However, the corrosion morphology and the severity varies from different ions contamination as the chemistry governing the corrosion differs from one ion to another. Our research is focused on key findings on corrosion of Aluminum bond pad due to chloride (Cl-) and fluoride (F-) contamination. Our central motivation is to identify this F- corrosion mechanism, so that it will help to develop a strategy to prevent it and study the comparison between Cl- and F- Corrosion using Micro-pattern corrosion screening technique, Wire-bonded device (WBD) and other characterization technique such as GC-MS, SEM and tafel. GC-MS reveals that H2 gas evolution is observed during Cl- corrosion of the WBD, whereas little or no H2 evolution is observed during F- corrosion. SEM and EDX reveals no presence of Cl- in the corroded areas of its corrosion, whereas strong F- signal is observed in F- corrosion of the bondpads revealing, that the corrosion products formed on the surface has very poor solubility showing that Cl- and F- has a complete different corrosion morphology. Striking contrasts in corrosion morphology observed during the Cl- and F- corrosion were explained in the present work and will lead to better understanding of factors influencing the bond pad corrosion leading to the wire bond failure in IC packaging devices. [Fig. 1] Figure 1

Corrosion behavior of duplex stainless steel reinforcement in ternary binder concrete exposed to natural chloride penetration

The corrosion behavior duplex stainless steel rebars embedded in concrete exposed to natural chloride penetration has been carried out. Three duplex stainless steels (DSSs) differentiated in the Ni, Mo and Mn content and two types of concretes elaborated with different binders, Portland cement and Portland cement blended with Slag and Limestone, were employed. The corrosion behavior was followed through Ecorr and Rp measurements along the exposure period. The tests were extended up to corrosion detection or to 2 years, and the chloride contents accumulated at the rebar level were determined.The DSS with lower Ni content has demonstrated to show lower corrosion resistance in presence of chlorides and pitting corrosion at lower chloride contents accumulated at the rebar level were detected. The DSSs embedded in OPC concrete resist better to corrosion in presence of chlorides than those rebars embedded in concrete containing blast furnace slag and limestone.

New insights into copper corrosion in presence of benzotriazole and chloride ions

ABSTRACTThe effect of Cl– concentration and temperature on the copper corrosion in NaCl solution in presence of 40 mg L–1 benzotriazole was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, electrochemical noise (EN) and scanning electron microscopy (SEM). Results revealed that the charge transfer resistance decreased with increasing the Cl– concentration and temperature. The EN generated at low Cl– concentration and low temperature had small noise amplitude, while the EN showed large potential oscillation amplitude in the case of high Cl– concentration and high temperature. A parameter, named corrosion active energy CAE, was proposed to further study the relationship between the EN feature and corrosion rate and corrosion severity (SEM). The variation trend of corrosion active energy CAE with Cl– concentration and temperature was found to be opposite with energy gap Eg and charge transfer resistance. Thus, CAE shows a promising potential to in situ evaluate the corrosion rate and corrosion severity.

Effect of Environment Variables and Material Properties on the Limiting Current Density for Oxygen Reduction

For aircraft alloys that have received surface treatments, primers, and topcoats to control self-corrosion due to precipitate phases, high-strength fasteners made of stainless steel or titanium alloys are the most obvious point of attack due to galvanic mismatches between the materials. However, the electrolytes that form from atmospheric processes can differ widely in composition and thickness. Dissolved oxygen concentrations vary due to temperature and salinity changes in the electrolyte. Recent attempts to model atmospheric corrosion have suggested that, at high salt loadings on the surface, electrolytes can form that have water layer thicknesses that appear as bulk electrolytes in terms of oxygen transport1. Experiments using rotating disk electrode (RDE) measurements and polarization curve data,2 have suggested an upper bound of approximately 800 mm on the diffusion layer thickness for oxygen that can be expected to form in a thin film of water. At distances beyond this thickness, convective flow is expected to dominate oxygen transport. In this report, we compare the results of RDE experiments that simulate thin film behavior on different substrate materials in different electrolytes with polarization data obtained under actual electrolyte thin films equilibrated at different relative humidity values, and bulk polarization measurements, as shown in Figure 1, in order to determine the effects of ohmic drop on the measurements and isolate relevant kinetic parameters. Isolating these effects is important in order to accurately model the corrosion currents arising from galvanic couples in which the oxides at which the reduction reactions are occurring can be changing in response to the changes in the electrolyte as the environment changes. Figure 1. Bulk cathodic polarization curves in 0.6M NaCl at 25◦C for Pt, UNS S31600, and UNS R56400. This work was sponsored by the Office of Naval Research, ONR, under grant/contract number N0001418WX00826; the views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Office of Naval Research, the U.S. Navy or the U.S. government. References 1 Van den Steen, N., Simillion, H., Dolgikh, O., Terryn, H. & Deconinck, J. An integrated modeling approach for atmospheric corrosion in presence of a varying electrolyte film. Electrochimica Acta 187, 714-723, doi:10.1016/j.electacta.2015.11.010 (2016). 2 Liu, C., Srinivasan, J. & Kelly, R. G. Electrolyte Film Thickness Effects on the Cathodic Current Availability in a Galvanic Couple. J Electrochem Soc 164, C845-C855, doi:10.1149/2.1641713jes (2017). Figure 1

Evaluation of alumina incorporated combined ceramic layer thermal barrier coating

In present work the coatings having lanthanum-titanium-aluminium oxide that is LaTi2Al9O19 (LTA) in combination with yttria stabilized zirconia (YSZ) and alumina (Al2O3), were developed using plasma spray method. Thus the top coat comprises of LTA/YSZ/Al2O3 ceramic top layer. The coatings were tested for type I hot corrosion in presence of Na2SO4 and NaCl salts in 3:1 mass proportion at 900 °C for 100 h. LTA 150 (having LTA top coat of thickness 150 μm) as-sprayed and annealed samples have shown excellent hot corrosion resistance upto 100 h. XRD patterns indicate that the LTA and Al2O3 phases were retained even after 100 h of isothermal hot corrosion with slight decrease in their peak intensity. Hot corrosion of alumina incorporated LTA coating resulted in the formation of LaAlO3, Na2Al2O4, NaAlO2.

Modeling Film Thicknesses and Estimating Corrosion Depths Under Climate Control

Atmospheric corrosion and accelerated corrosion tests are inherently subjected to dynamic film variations. Modeling and understanding these variations in combination with corrosion processes is therefore of high relevance. From a modeling point of view, accelerated corrosion tests have the advantage of well defined conditions which can be used as an input for the models. From experimental point of view, these models can be of high value because notwithstanding the defined conditions, experimental results of accelerated tests are often difficult to reproduce exactly. This is where models may be able to help in the understanding of the phenomena. In [1] a model to predict the time dependent film thickness was presented, taking into account the relative humidity, temperature, substrate material and the presence of hygroscopic salts. A simple corrosion model was used to calculate a simulated corrosion depth. A simple corrosion model allows to focus on the effect of the film thickness. Based on this work, we present experimental and simulated corrosion depths in accelerated corrosion tests. The corrosion depth is measured using AirCorr loggers. The electrical resistance of a thin metal track is measured and registered over time. As the corrosion processes will decrease the cross-sectional area of the track, the resistance will increase. A reference electrode provides the possibility to compensate for temperature effects. We focus on corrosion depths as measurements on the liquid film thickness itself are not directly available in literature. Several cycles VDA, N-VDA, GMW, etc are simulated and compared with measurements considering a iron substrate. An exact match between the experiments and simulations is not expected, as important phenomena are not (yet) included in the model. For example, run-off effects on the film thickness and the amount of salt on the surface, effects of the corrosion products on the corrosion processes (passivation, blocking) and on the film thickness (hygroscopic effects). What we expect to see similar trends between measurement and simulation, linked with the electrolyte thickness. We study also the effects of different parameters on the results. During the saltspray, a constant film thickness is assumed. In the figure we show the simulated corrosion depths obtained in a partial N-VDA test when different film thicknesses during this spraying phase (50micron, 100micron, 150micron) are assumed. These results are compared with experimental data. Based on the comparison, conclusions are formulated about the accuracy of the model, the applicability, the shortcomings and the points of interest for future work are identified. [1] Van den Steen, N., et al. "An integrated modeling approach for atmospheric corrosion in presence of a varying electrolyte film." Electrochimica Acta 187 (2016): 714-723. Figure 1

Inhibition of Acid Aluminum Corrosion in Presence of Aqueous Extract of Domiana

Inhibition of Acid Aluminum Corrosion in Presence of Aqueous Extract of Domiana

An integrated modeling approach for atmospheric corrosion in presence of a varying electrolyte film

A Dynamic Electrolyte Film Corrosion (DEFC) model is presented that integrates a model for uniform film condensation/evaporation in presence of salts with a simple model of iron corrosion. The focus is on the role of the film thickness. A limited number of measurements confirms that it is unavoidable to consider the hygroscopic effects. The model is used to simulate the role of sample thickness, heat transfer and changing rates of temperature and relative humidity in well defined climate chamber conditions. Obtained film thicknesses and corrosion rates are simulated using identical input data in absence of salt and for two salts (NaCl and a seawater-like mixture of 90%NaCl-10%MgCl2). The large indirect influence of salts on the corrosion is discussed. Also one-week simulations are performed based on recorded and averaged meteorological data. They show that averaged meteorologic data will lead to incorrect results.

Pitting corrosion and stress corrosion cracking study in high strength steels in alkaline media

Steel reinforcement in concrete is protected from corrosion by passivation due to the high alkalinity of the cement pore solution, but the presence of aggressive ions as Cl− could induce pitting corrosion processes thus decreasing the durability of the structure. This also occurs for prestressing concretes but the risk to suffer pitting corrosion in presence of aggressive ions, and hence stress corrosion cracking (SCC), increases due to the external mechanical load. The study of the corrosion processes by classical methods involves the determination of pitting potential (E pit) or the polarization resistance monitoring during long periods (i corr). However, the large number of parameters, which could potentially influence the determination of the E pit or the i corr values, result in a great variety of results in literature. The present study proposes a simple and reliable method to evaluate the susceptibility to suffer pitting corrosion process and stress corrosion cracking by the induction of pitting corrosion process by cyclic voltammetry. The pitting corrosion intensity is evaluated by means of the charge during the corrosion process, and related with the weight loss and the decrease of the mechanical properties of the steel under external load. The results show a linear and a volcano trend when pitting corrosion process and stress corrosion cracking are respectively evaluated.

On the Mechanism of Corrosion in Presence of Organic Acids

Theories on the role of organic acids in general, and acetic acid in particular, in carbon steel corrosion were initiated in 1940s with the reports on the significant effect of acetic acid in pipeline corrosion in oil and gas industry1. It was reported that even small amounts of acetic acid (300 ppm) can cause severe corrosion of pipeline steel1. Later on, several studies on the concentration of organic acids in formation water of oil and gas wells have been reported up to 3000 ppm of acetic acid1–4. Despite numerous studies on the mechanism of acetic acid corrosion of pipeline steel, details of the mechanism are still debated. Acetic acid is known as a week acid which is partially dissociate in water. It is also known that weak acids act as a reservoir for hydrogen ions in the corrosion process. This phenomenon known as “buffering effect”, describes the enhanced limiting current in presence of acetic acid compared to the case of strong acids at a similar pH. Additionally, it is suggested that the undissociated acetic acid is also a proton donor and is able to be reduced at the surface of the steel, which is known as “direct reduction” mechanism. The direct reduction mechanism has been used for years5,6. Also, many other studies on the combined effect of acetic acid and carbon dioxide on carbon steel have adopted the same mechanism7–9. However, recent studies suggest that undissociated acetic acid is only involved in the corrosion process as a buffer for hydrogen ions. Tran et al.10 report a series of polarization curves on SS304 stainless steel, showing that the concentration of acetic acid does not affect the charge transfer portion of the cathodic sweeps. Therefore, they have concluded that acetic acid is not involved in charge transfer processes directly and that the buffering effect is the main mechanism. In that study, authors suggest that the same mechanism is valid for carbon steel. In the present study an iron electrode was used instead of carbon steel in order to minimize the effect of impurities such as carbon. Figure 1 presents the experimental data collected in the present work and the comparison with the results of the mathematical simulations. The experimental data are collected using a rotating disk electrode made from pure iron exposed in a two liter, three electrode glass cell in deoxygenated aqueous solution. The mathematical simulation is the solution of Nernst Plank equation for an acetic acid aqueous system. These equations are solved with finite difference method, using Newman’s BANDJ11 algorithm in FORTRAN with a MATLAB user interface. Figure 1 shows a clear linear cathodic charge transfer behavior at both pH values. Additionally the charge transfer part of the cathodic reactions is insensitive to changes in concentration of acetic acid which is the indication that free acetic acid in the system is not directly reduced at the surface of iron. Current results confirm that the proposed mechanism by Tran et al. applies to pure iron which has great similarity to pipeline steel. The mathematical calculations proposed here also support the same conclusion. Additionally, comparison of the calculated charge transfer rates based on these results suggests that the rate of dissolution of iron is slightly retarded in presence of acetic acid.

Protein Interactions with Corroding Metal Surfaces

Low-corrosion resistant metals, such as Mg or Fe based alloys, have been in the focus of intensive research activities in recent years to be used in biodegradable implants. A general challenge is to tailor the materials and surfaces to achieve the desired and controlled corrosion rate for the targeted applications. A further challenge is to elucidate the influence of the complex biological environment on the corrosion mechanisms of these materials. A vast majority of the studies in this field have been carried out on Mg based materials; far less attention has been given to Fe. A comparison of the behavior of Fe and Mg based alloys in simulated biological environments is on one hand side of practical interest in view of possible biomedical applications of these materials. Moreover, from mechanistic point of view, a direct comparison may aid in elucidating mechanisms of interactions between the constituents of the biological environment and the corroding metal surfaces in more detail. In the present study, we are investigating the influence of proteins on the corrosion behavior of Mg and Fe by electrochemical and surface analytical techniques. Proteins in solution can have multiple effects on corrosion reactions: on one hand side, protein adsorption layers can block electrochemically active surface sites and therefore slow down corrosion. Protein adsorption will be influenced by the surface chemistry of the metals (e.g., wettability, type of oxides/hydroxides formed on the surface, and the resulting surface charges) - therefore different interactions may be expected for Mg and Fe. On the other side, complexation of metal cations can take place by proteins (and amino acids), thereby reducing the free cation concentration and possibly accelerating corrosion. Also this effect depends on the nature of the metal cations; for Fe and Mg dissolution products different strength of interactions can be expected. Electrochemical studies indeed indicate very different interactions of proteins (bovine serum albumin, BSA) on Mg as compared with Fe. For Mg, inhibition of corrosion in presence of albumin in solution can be observed for short-term experiments. For Fe, a slight increase of corrosion by addition of albumin in solution takes place. In general, the influence of BSA on the corrosion behaviour of Mg is much stronger than that observed for Fe. Surface analytical studies (XPS and ToF-SIMS) demonstrate stronger adsorption of albumin on Mg than on Fe. Moreover, protein adsorption on Mg and Fe varies for different proteins (for instance: albumin vs. lysozyme). Possible mechanisms and critical factors of protein interactions with corroding Fe and Mg surfaces will be discussed.

Protective Efficiency of the Oil Composition Coatings Against Carbon Steel Atmospheric Corrosion in the SO2 Presence

The protective properties of the compositions on base of the industrial oil or transformic one and oilsoluble inhibitor IFHAN 29-A (the product of the catalytic interaction between tall oil production waste and higher aliphatic amines) have been studied with respect to carbon steel in the atmosphere containing 0.1 – 10 vol.% SO2 at the different humidity (70 – 100%) and room temperature.IFHAN 29-A shows the thickening ability with respect to industrial and transformic oils in the 293 – 353K temperature range. It allows to deposit the oil coating films of 20 ± 5 μm thickness on the metal surface. These films provide a protection of carbon steel against atmospheric corrosion in the presence of SO2. A growth of the inhibitor concentration in the oil composition film results a sharp increase of the protective efficiency in the presence of SO2 in comparison with the conditions without SO2. The oil nature doesn’t practically influence on the qualitative and quantitative character of the dependences. Protective efficience of the oil compositions reaches 80%.Kinetics of the cathodic and anodic processes on steel has been investigated in the 0.5 M NaCl solutions in the presence of SO2. A growth of the SO2 volume concentration in the air phase increases the cathodic limiting diffusion current density in the absence of the protective oil composition film on the electrode surface, but does not practically influnce in the presence of the coating. A dependence of the anodic ionisation rate on the SO2 concentration in the presence of the protective oil composition film has an unmonotonous character. The observed results are discussed with taking into account an interaction between SO2 and water leading to a formation of the SO2 .H2O hydrate and the [SO2]/[H2SO3] correlation equal to 20 in the aqueous solution.

Kinetics and mechanism of the anodic dissolution of gold in solutions of 1,5-diazabicyclo[3.1.0]hexane and its precursors

Studies of the electrochemical behavior of hexahydropyrimidine, 1,5-diazabicyclo[3.1.0]hexane, and 1,3-diaminopropane on a gold electrode via cyclic voltammetry allow us to conclude that gold anodes are subject to corrosion in presence these compounds, yielding complexes that migrate into the solutions and discharge on the counter electrode, producing gold metal deposit. 1,5-Diazabicyclo[3.1.0]hexane is found to form complexes with gold that are much more stable that those formed by hexahydropyrimidine and 1,3-diaminopropane.

Influence of CeO2 superficial coating on the high temperature corrosion behavior of 2.25 Cr-1 Mo Steel in SO2 + O2 atmospheres

The influence of superficial CeO2 coatings on isothermal and cyclic high temperature corrosion behavior of 2.25 Cr-1 Mo steel in oxidation and sulfidation (SO2 + O2) atmosphere have been reported in this paper. The CeO2 coating of three different depositions rate (0.15 mg/cm2, 0.30 mg/cm2 and 0.50 mg/cm2) were prepared for experimental investigations. The isothermal corrosion study of uncoated and CeO2 coated specimens was carried out in SO2 + O2 environment at 973K for 150 hours. The results clearly indicate that CeO2 coated specimen improves the high temperature corrosion resistance than uncoated specimens. The post corroded CeO2 coated specimen shows reduction of scale growth and improved scale adhesion to the substrate. The cyclic corrosion study was also carried out in both coated and uncoated specimen in same environment at 973K for 100 h. The CeO2 coated specimens on thermal cycling also shows significant improvement of the corrosion resistance without scale cracking and spallations. In contrary, the uncoated specimen in both isothermal as well as cyclic environment shows higher corrosion rate along with scale cracking and spallations. The results of the reaction kinetics have been substantiated by post corrosion analysis of alloy/scales combinations by SEM and XRD. The details mechanism of the corrosion in presence of CeO2 coating was further discussed in the paper.