Corrosion Rate Of Coatings Research Articles

Corrosion Resistance of Zinc and Zinc-Aluminum-Magnesium Coatings in Atmosphere on the Territory of Russia.

Zinc-coated carbon steel is commonly used in the construction of buildings, infrastructure objects such as roads and bridges, automotive production, etc. Coatings based on zinc-aluminum-magnesium alloys that may have better corrosion resistance than zinc have been developed. The coatings made of the new alloys have been available on the market for a shorter period of time than conventional zinc coatings. This paper presents data on the corrosion resistance of zinc and zinc-aluminum-magnesium coatings on carbon steel obtained by tests in four locations in Russia with marine and non-marine atmospheres. Four one-year exposures at the beginning of each season and two-year tests were performed. It is shown that the corrosion resistance of the coatings depends significantly on the beginning of the exposure. The categories of atmosphere corrosivity in relation to the coatings were determined at each location. Based on the dose-response function (DRF) for zinc developed for the territory of Russia, DRFs for the coatings were obtained. A match between the categories of atmosphere corrosivity determined by the first-year corrosion losses and estimated from the values of corrosion losses calculated using the DRF is shown. Based on the data of two-year tests, the variation in the corrosion rate over time is obtained. The corrosion rates of the coatings in the territory of Russia are compared to the corrosion rates of coatings observed in various locations around the world. An approximate estimate of the service life of the coatings at the test sites is given.

Effect of Nb content on microstructure and corrosion resistance of Inconel 625 coating formed by laser cladding

The Inconel 625 coatings with Nb addition of 0 %, 1.5 %, 3 % and 5 % were prepared by laser cladding technology. The effects of different contents of Nb on the phase composition, microstructure and corrosion resistance of the coatings were investigated by XRD, SEM, electrochemical test and other techniques. The results show that with the increase of the Nb content, the surface structure of the coating changes from dendrites to cellular crystals. Because of the consumption of C in γ-Ni phase by forming NbC, more Cr was released from its carbide state and solidly dissolved in γ-Ni phase, which improves its passivation capacity in the electrolyte. The increase of Nb also promotes more Nb and Mo elements to participate in the oxidation process. The plugging of pitting holes by corrosion products reduces the corrosion rate of coatings. The 3Nb coating exhibited the best corrosion resistance in 3.5%NaCl solution. The addition of an appropriate amount of Nb is an effective way to optimize the coating's microstructure, improve its corrosion resistance and microhardness.

Corrosion of diffusion zinc coatings in sodium chloride solutions

Diffusion galvanizing is widely used in the pipe industry for coating the threaded surface of pipe couplings, protecting water and gas pipelines, and other metal products. Diffusion coatings have a number of advantages over other types of zinc coatings. In this work, electrochemical and gravimetric methods are used to study the corrosion behavior of diffusion zinc coatings in sodium chloride solutions. The corrosion rate depends non-linearly on the thickness of the coating. At the initial stages, the corrosion rate of coatings depends on the structure of the phases on the surface, and with an increase in the holding time, the corrosion rate depends to a greater extent on the properties of the products formed during the corrosion process. Films of corrosion products of diffusion zinc coatings consist of zinc oxide/hydroxide and basic zinc salts, while the composition of the film changes with increasing coating thickness.

Optimization of Corrosion Rate of Coatings Using RSM and Particle Swarm Optimization Algorithm

This study focuses on the electroless deposition of Ni–P alloy over a copper substrate to minimize the corrosion rate of the substrate. Central Composite Design (CCD) has been performed using Design-Expert software for minimizing the corrosion rate of the coating. Along with that, CCD is also utilized to analyze the influence of various process parameters viz. concentration of Nickel Sulphate, the concentration of Sodium Hypophosphite and bath temperature. Potentiodynamic test has been employed to evaluate the corrosion rate of each of the coated substrates. In order to minimize the corrosion rate, optimization has been performed using particle swarm optimization (PSO). 21.59[Formula: see text]g/L of Nickel Sulphate, 26. 72[Formula: see text]g/L of Sodium Hypophosphite and 93.41°C as the bath temperature were the optimum conditions for the deposition of coating in order to achieve a corrosion rate value of 0.862[Formula: see text]mm/Yas obtained from the model analysis results. Further, Analysis of Variance (ANOVA) was implemented which corroborated that the parameter Nickel Sulphate along with the interaction between Sodium Hypophosphite and bath temperature were the significant ones in determining the corrosion rate of the coating deposited in optimized condition. Optical Microscopy, Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray analysis (EDX) were conducted to study the surface morphology and the elemental composition of the coated substrate respectively.

Modeling the wetting of titanium dioxide and steel substrate in water-borne paint and varnish materials in the presence of surfactants

This paper reports the results of studying the effect of two additives such as polyether siloxane (PS) and sodium polyacrylate (SPA) on the wetting of various substrates in water-borne paints (WB paints). Titanium dioxide (TiO2), paraffin (PA), steel (ST), and glass (GL) were used as solid substrates. The edge wetting angle (θ0) and the ratio (dCosθ/dСS) were used as the criterion for assessing the wettability of solid substrates. In aqueous solutions (without acrylic resin), both surfactants improve the wetting of the substrates. For PS, all the substrates studied, depending on θ depression, can be arranged in a row: ST>PA>GL>TiO2. For SPA: PA>TiO2>GL>ST. The introduction of an acrylic film-forming agent in the composition enhances the wetting ability of SPA (in comparison with the aqueous solution of surfactants). With an increase in the concentration of SPA from 0 to 4 g/dm3 in acrylic resin solutions, the edge wetting angle of steel decreases by 6÷8° (while in water by only 3°). With respect to TiO2, the wetting activity of SPA does not depend on the acrylic content of the water. PS in acrylic-containing compositions exhibits worse wetting activity than SPA. The introduction of surfactants in the compositions improves the quality of coatings. With optimal SPA contents in the compositions, the corrosion rate of coatings is reduced (in distilled water by 45 %, in 60 % NaCl solution by 60 %). At the same time, the gloss of coatings increases by 50 % while adhesion increases by 2 points (according to ISO 11845: 2020). This is fully correlated with the nature of the effect of surfactants on the wetting of the steel substrate and pigment (titanium dioxide). Based on probabilistic-deterministic planning, the compositions of WB paints were optimized, ensuring their maximum wetting of TiO2 and ST. Equations for calculating cosθ depending on the content of acrylic polymer and surfactants have been derived

Hydrothermal synthesis of nanocrystalline hydroxyapatite\u2013graphene nanosheet on Ti-6Al-7Nb: mechanical and in vitro corrosion performance

The hybrid coatings containing the graphene nano-sheet (GNS) and nano-hydroxyapatite (nHA) phases have been successfully synthesized on Ti6Al7Nb alloys by a one-step hydrothermal method. The hydrothermal reaction was carried out for 24 h at 200 °C. The GNS ratio has been altered as 1, 3, 5 and 7 wt.% in the coatings and, the results have compared with non- GNS containing coatings. The effect of the GNS ratio on the microstructure, hardness, and in vitro corrosion responses has been investigated in detail. The characterizations of the coatings were carried out by SEM, EDS, AFM, XRD and, FTIR. The corrosion behavior of the hybrid coatings was compared in Kokubo’s solution at 37 °C by using potentiodynamic polarization tests. The results showed that the hydroxyapatite phases were deposed on the graphene layers with nano-size nucleation with its Ca/P stoichiometric ratio. The best hydrophilicity (~52°) property has been obtained in nHA/3GNS coatings. In addition, the corrosion rates of coatings increased in the following order: nHA/3GNS < nHA/1GNS < nHA/7GNS < nHA/5GNS < only nHA.

Correlating the Five-Parameter Grain Boundary Character Distribution and Corrosion Behavior of Zinc-Carbon Nanotube Composite Coatings

Grain boundary engineering (GBE) of coatings using optimum weight fractions of foreign inclusions can improve corrosion resistance performance. This is illustrated here by correlating the corrosion behavior with the five-parameter grain boundary character distribution analysis of Zn-carbon nanotube (Zn-CNT) composite coatings. Zn-CNT composite coatings with different volume fractions of CNTs were electrodeposited on mild steel substrates by dispersing different amounts of CNTs (4, 6, 8, 10, 15, and 20 mg/L) in the Zn electrolyte bath. All the coatings exhibited compact and crack-free morphology. Electrochemical impedance spectroscopy (EIS) measurements were conducted in 3.5 wt pct NaCl solution. The Nyquist and Bode plots showed a decrease in the coating corrosion rate with initial CNT addition up to the Zn-CNT3 coating (produced from 8 mg/L of CNT in the electrolyte), after which the corrosion resistance decreased with continued addition of CNTs. This showed that an optimum exists for CNT in the Zn coating to achieve high corrosion resistance performance. Orientation distribution maps from the coating cross section were acquired using the electron backscatter diffraction (EBSD) technique for correlating the microstructure with the corrosion data. The lower corrosion rate in the Zn-CNT3 coating was attributed to the strong basal plane texture in grains along the growth direction. The angle/axis misorientation showed that most grain boundaries have [ $$ 2\overline{11} 0 $$ ] and [ $$ 10\bar{1}0 $$ ] axis misorientations signifying special grain boundaries. The five-parameter analysis showed that these grain boundaries are mostly symmetric and tilt boundaries, which are low-energy boundaries, whereas in Zn and Zn-CNT6 (produced from 20 mg/L of CNT in the electrolyte) coatings, the higher corrosion rates were due to the high fraction of high-angle grain boundaries (HAGBs), grain texture along the growth direction that corresponds to an orientation that is active in the corrosive environment, and the absence of special grain boundaries.

EFFECT OF THE ELECTRODEPOSITION CONDITIONS ON THE EROSION CORROSION OF AUSTENITIC STAINLESS STEEL 316L USING RESPONSE SURFACE METHODOLOGY (RSM)

This study represents an attempt to improve the erosion corrosion resistance for industrial pumping station used to produce sulfuric acid through electrodeposition coating samples of Austenitic stainless steel 316L. Minitab 19 program was used to precipitate a composite coating layer (Cr-WC) because it is used in many industrial applications that require corrosion resistance, As well as high hardness. The samples were coated using different variables as inputs: temperature(T), WC concentration(WC wt% ), stirring velocity (r.p.m) and deposition time (t) for four levels using central composite design for design laboratory experiments. The factors of coating thickness (C.T), surface roughness (Ra) and micro- hardness (HV) were adopted as outputs response and a complete analysis of variances (ANOVA) at constants significances levels of %5, was done to fully identify the most significant parameters.The surface response methodology (RSM) was used to provide an optimized model with the best optimum properties such as micro-hardness, surface roughness, coating corrosion rate and oxidation corrosion rate to improve the corrosion resistance of Austenitic 316L stainless steel samples.The results showed respectively that the wc wt.% was the most effective on all the outputs response then deposition time (min), temperature(T) and stirring velocity (r.p.m).

Polyester-graphene primer coatings: corrosive and mechanical properties

This study developed and characterized of the polyester (PE)-graphene (GR) primer coating in corrosion resistance and mechanical properties. PE coatings varied with 0-8% of GR were prepared using ultrasonication method and undergone the morphology characterization using Field Emission Scanning Electron Microscopy (FE-SEM), and also being evaluated using various corrosion and mechanical tests, namely tafel test, immersion test, adhesion test and hardness test. The FE- SEM analysis shows that the homogeneous dispersion of GR in PE resin at 2% of GR loading, whilst at higher loading of GR produced agglomeration that reduced the corrosion inhibition properties of the coatings. The corrosive properties were characterized using autolab potentiostat for determination of corrosion rate and immersion testing using 3.5% NaCl for 9 days. The results show that the optimum corrosion rate of coatings was found at 2% of GR loadings which is 0.586 mmpy. This is due to at 2% GR is optimum as a physical barrier and inhibit the diffusion pathways of corrosive species as there is no agglomeration of GR which is showed that very well dispersion of GR in the PE resin. Whilst, immersion observation also shows the optimum condition at 2% of GR loading, which has a lower corrosion property. On the other hand, adhesion and hardness testing were enhanced by increasing of GR loadings (0-8%) as the properties of GR imparted high strength, rigidity, and durability. Therefore, the incorporation of GR is very efficient materials to enhance both mechanical and corrosive properties of polymeric coatings.

Mechanical Properties and Corrosion Resistance of Hard β-W based CVD Coatings in Aqueous NaCl Solution

The paper presents the results of studying the mechanical and anticorrosive properties of coatings based on the metastable tungsten phase (β-W) obtained by means of low-temperature chemical vapor deposition from fluorine-containing media. Corrosion studies in a 5% aqueous solution of NaCl showed that the general corrosion rate of W-based coatings reaches the value of 60 μm/year. The positive correlation between the corrosion rate of coatings and their hardness indicates a significant effect of the stressed state of the coatings on their corrosion behavior.

Evaluation of corrosive behavior of chromium silicon nitride under hydrodynamic conditions in aggressive environments

In order to analyze corrosion resistance and wear behavior, steel cylinders were coated with chromium silicon nitride via physical vapor deposition, using a reactive sputtering magnetron, with base and working pressures of 4*10−6 mbar and 8*10−3 mbar respectively. The diffraction patterns correspond to chromium nitride and the amorphous phase of silicon nitride, hardness of 6.52 GPa, thickness of 3 μm and chemical composition characterized by nitrogen, silicon and chromium. The corrosion behavior was determined with a rotating cylinder electrode, rotating at different speeds and connected to a Gamry potentiostat galvanostat, using the techniques of polarization resistance, electrochemical impedance spectroscopy and dynamic potentiation polarization. The tests were carried out in solutions composed of water, 1% of sodium chloride and silica sand, with temperatures of 25 °C and 45 °C. Limiting current density behavior was evidenced. The coating corrosion rate was reduced by up to two orders of magnitude compared to that found for steel samples and was affected by the system rotation speed, particle size and electrolyte temperature.

Peculiarities of zinc coating corrosion in neutral environments with inhibitors based on benzotriazole, cyclohexylamine and morpholine

The influence of domestic VNKh-L type nitrogen-containing corrosion inhibitors on the corrosion patterns of zinc coating on steel in a neutral environment was investigated. The paper aims to study the structure of the corroding zinc coating surface, as well as the influence of conditions simulating the degradation of inhibitors under actual application conditions on their protective properties. Mechanical activation in a ball planetary mill was used to simulate the thermal and deformation conditions of inhibitors. Zinc coating corrosion on steel was carried out in a sulfate-chloride environment simulating atmospheric corrosion and in borate buffer solution. The concentration of inhibitors in corrosion environments was 0,2 wt.%. The corroded surface morphology of the zinc coating was studied using the Philips SEM-515 scanning electron microscope (at an accelerating voltage of 10 kV) with an X-ray micro probe. Studies of the zinc coating corrosion rate on St 08 were carried out by the indirect measurement of corrosion resistance using the MONIKOR-1 corrosion meter. Borate buffer solution (Na2B4O7 + H3BO3, pH = 6,6) and the solution simulating atmospheric corrosion (NaCl + + Na2SO4, pH = 6,0) were used as corrosive environments. The corrosion rate of samples in corrosive environments without inhibitors was taken as 1. Exposure time of each sample in corrosive environments was 3 h. The chemical composition of corrosion products was studied by mirror reflection in the IR range. The IR spectra of metal plate surfaces were recorded on the FSM-1202 IR Fourier spectrometer in a wavelength range of 450–4000 cm–1 with a resolution of 2 cm–1 and an accumulation of 100 scans. A mirror reflection attachment with a 10° angle of incidence was used to obtain reflection spectra. The zinc coating corrosion rate in sulfate-chloride and borate environments in the presence of inhibitors based on benzotriazole and cyclohexylamine was virtually not reduced compared to the corrosion rate in the same environments without inhibitors. When both initial and mechanically activated inhibitors based on morpholine and benzotriazole are added to the corrosion environment, the iron corrosion rate decreases compared to the corrosion rate in the same environments without inhibitors. In the presence of initial and mechanically activated inhibitors of both groups, pitting corrosion of the zinc coating in the studied corrosion environments is observed. At the same time, the pitting depth under corrosion conditions is less than the zinc coating thickness.

Evaluation of organic coatings for corrosion protection of condensing economizers

A corrosion protection of Stainless Steel (Grade 304) with low-cost commercial organic coatings (paints) was investigated in this study. Air sprayed Polyurethane (PU)-, Epoxy- and Acrylic-based commercial paints on the above substrate were tested for their anticorrosion properties in prospect of potential application for the protection of condensing economizers from industrial flue gases. PU and Epoxy coatings exhibited better corrosion protection efficiency of stainless steel than the acrylic coatings with values of 40, 39 and 28.1% respectively. This is in total agreement with corrosion current density trend calculated from potentiodynamic polarization curves. Corrosion rates of coatings in 3.5% wt NaCl aqueous solutions were calculated at 0.065, 0.067 and 0.071 mpy for Epoxy, PU and Acrylic coatings respectively. Condensation phenomena and water collection rates (WCR) at various conditions are also provided. The highest WCR exhibited on the epoxy coatings reaching 1.987 ml m-1h-1 at 40oC and 100% RH. These data provide a full dataset for the designers of condensing economizer systems willing to incorporate organic coatings either at structural components or as touch up solutions.

Anticorrosion performance of chromized coating prepared by pack cementation in simulated solution with H2S and CO2

A hash service environment containing H2S and CO2 in oil industry usually causes corrosion of carbon steel. In this study, the chromized coatings with different deposited time were prepared on the surface of carbon steel by the method of pack cementation to enhance its corrosion resistance. Then the microstructure, hardness, corrosion resistance as well as the semiconductor behavior of coatings in the simulated solution with saturated H2S and CO2 were investigated. The results show that the content of Cr in coating was increased by prolonging deposited time, and both chromium carbides and chromium nitrides were formed. Furthermore, coatings display higher polarization resistance, Rp, than that of the substrate, indicating a higher resistance to charge transfer on coating surface. The corrosion rates of coatings with different deposited time were significantly lower than that of substrate. Chemical analysis showed the formation of heavy sulfides on the surface of substrates after corrosion, while the least corrosion products were detected on the surface of coating with deposited time of 12h. Mott-Schottky results indicated that coating of 12h displayed less defects than the other two coatings with deposited time of 4h and 8h, which will be beneficial to improve corrosion resistance. The investigation showed that chromized coatings exhibited high corrosion resistance and owned a potential application in oil industry for corrosion prevention.

Effect of Process Parameters on the Corrosion Resistance Properties of PEO Coatings Produced on AZ31B Magnesium Alloy

The automotive sector is particularly interested in magnesium alloys, which can decrease the weight of the vehicle leading to improved fuel efficiency and decreased emissions. However, poor corrosion resistance, especially in solutions containing chlorides, is a major limitation for its widespread exploitation in exposed automotive applications. Plasma electrolytic oxidation (PEO) coatings have been shown as a promising technology to improve the corrosion resistance of magnesium alloys 1. The properties of PEO synthesized coatings have been shown to significantly dependent on the process parameters employed to produce them2,3. Understanding the influence of process parameters on the overall corrosion resistance of AZ31 is essential if PEO technology is to be used in an industrial application. The present investigation examines the effect of processing time, current density, and electrolyte temperature on structural morphology of PEO coatings made on AZ31B linked to their corrosion resistance. PEO coatings were produced using a sodium silicate basic electrolyte using current densities ranging between 10 mA/cm2 and 20 mA/cm2. The temperature of the electrolyte was varied between 10-40ºC, while the processing time was varied between 15 and 30 minutes. The overall corrosion rate of PEO-coated samples was evaluated using mass loss testing and electrochemical impedance spectroscopy (EIS), while the composition and morphology of the PEO coatings were analyzed using a combination of x-ray diffraction (XRD), electron microscopy, and white light profilometry. The phase composition of the synthesized PEO coatings was analysed using XRD, see Figure 1. Spectra indicated that the PEO coating comprised two main phases, namely magnesium oxide (MgO) and forsterite (Mg2SiO4). The ratio between magnesium oxide and magnesium silicate was estimated via the reference intensity ratio (RIR) analysis. The mass ratio (MgO/Mg2SiO4) for PEO coatings made on AZ31B decreased from 0.63 (10 mA/cm2) to 0.11 (20 mA/cm2). The observed increase in the weight fraction of forsterite when higher current densities were is related to polymerization of silicate ions during the deposition process. It has been previously reported that the extremely high energy generated by the plasma discharges promote polymerization of the silicate4. Increasingly favorable polymerization resulted in greater incorporation of silicates into the coating, ultimately leading to higher weight fraction of forsterite and lower weight fraction of magnesium oxide. The corrosion rates of the two coated specimens (10 mA/cm2 and 20 mA/cm2) in addition to the bare metal AZ31 substrate were measured by 5-day mass loss testing in a 0.086M NaCl solution, see Figure 2. Both PEO coatings exhibited significantly improved corrosion resistance properties compared to as-received AZ31. The corrosion rates of coatings produced using an applied current density of 10 mA/cm2 were significantly lower than those of coating produced using a current density of 20 mA/cm2. The current research effort is focusing on providing explanations for observed differences in corrosion resistance properties of PEO produced when applying different current density values. The effect of changes in processing time and electrolyte temperature is also under investigation.

Corrosion Resistance of Ni-CeO&lt;sub&gt;2&lt;/sub&gt; Nanocomposite Coating Prepared by Electrodeposition with Rotating Cathode in an Ultrasonic Field

Ni-CeO2nanocomposite coatings were prepared by electrodeposition with rotating cathode in an ultrasonic field. The surface morphology of the coatings was examined. Effects of different electrodeposition methods, ultrasonic power and cathode rotating speed on the corrosion rate of Ni-CeO2nanocomposite coatings were analyzed. The results show that the corrosion rate of the coatings decreases considerably with the increasing of ultrasonic power, and suitable cathode rotating speed could decrease the corrosion rate of coatings. During the process of electrodeposition, the CeO2nanoparticles, ultrasonic and rotating cathode influence on the surface morphology of the coatings. The nanocomposite coating obtained by rotating cathode in an ultrasonic field exhibits refined crystal grains and presents an excellent corrosion resistance.

Characterization of the corrosion behaviour of Zn and Zn alloy electrodeposits: Atmospheric and accelerated tests

The corrosion behaviour of unchromated Zn, Zn-Co (0.6%), Zn-Fe (0.4%) and Zn-Ni (12%) coatings deposited from alkaline cyanide free solution was studied in a humid tropical climate and in accelerated chloride and sulfur dioxide cabinet tests. The presence of Ni or Co in the Zn matrix increases Zn coating corrosion resistance, while Fe does not change it. The statistical analysis of the data obtained showed that the specimens corrosion losses can be represented as an exponential equation as a function of time of wetness. In such case the corrosion losses in one year of wetness can be approximated as a linear function of accumulated Cl − and SO 2 pollutant deposition. The data indicate a more significant SO 2 influence on the coating corrosion rate that is due to Cl −.

MODIFICATION OF THE COMPOSITION OF LASER WELDS IN ELECTROGALVANIZED STEEL AND THE EFFECT ON CORROSION PROPERTIES

Abstract Compositional modification of the weld metal during laser welding of electrogalvanized steel sheet was achieved by the injection of metal powder or by a technique in which zinc that had been volatilized as a result of the welding operation was redeposited on the weld bead. Corrosion testing by means of the linear polarization technique showed that the coating corrosion rate in the case of laser welds containing redeposited zinc was substantially lower for an initial period than for normal laser welds. Only a small decrease in corrosion rate was achieved by the injection of tool steel powder during laser welding while an increase in coating corrosion rate was produced by the injection of nickel powder or stainless steel powder

Electrochemical investigation of the corrosion rate of sacrificial coatings on steel

Potential-time and linear polarisation data for commercial metallic coatings on steel strip in 1 N NaCl solution have been determined to investigate the connection between the coating corrosion rate and the difference in potential of the coating and steel. High coating corrosion rates were associated with large difference in potential with steel.

Radioactive tracers used to measure bearing wear : M. W. Savage and L. O. Bowman. Pipe Line Industry, v. 8, Feb. 1958, p. 36–40

A hash service environment containing H2S and CO2 in oil industry usually causes corrosion of carbon steel. In this study, the chromized coatings with different deposited time were prepared on the surface of carbon steel by the method of pack cementation to enhance its corrosion resistance. Then the microstructure, hardness, corrosion resistance as well as the semiconductor behavior of coatings in the simulated solution with saturated H2S and CO2 were investigated. The results show that the content of Cr in coating was increased by prolonging deposited time, and both chromium carbides and chromium nitrides were formed. Furthermore, coatings display higher polarization resistance, Rp, than that of the substrate, indicating a higher resistance to charge transfer on coating surface. The corrosion rates of coatings with different deposited time were significantly lower than that of substrate. Chemical analysis showed the formation of heavy sulfides on the surface of substrates after corrosion, while the least corrosion products were detected on the surface of coating with deposited time of 12 h. Mott-Schottky results indicated that coating of 12 h displayed less defects than the other two coatings with deposited time of 4 h and 8 h, which will be beneficial to improve corrosion resistance. The investigation showed that chromized coatings exhibited high corrosion resistance and owned a potential application in oil industry for corrosion prevention.