Influence of the Immersion Time and Temperature on the Corrosion of API X52 Steel in an Aqueous Salt Medium (original) (raw)
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International journal of electrochemical science
The effect of increasing the immersion time form 1 h to 24 h on the corrosion behavior of API X-70 pipeline steel in 4.0 wt. % NaCl solution was reported using different electrochemical and spectroscopic techniques. The cyclic potentiodynamic polarization (CPP) measurements indicated that increasing the time of immersion decreases the anodic, cathodic and corrosion currents. Chronoamperometric current-time (CCT) experiments at-0.5 and-0.35 V vs. Ag/AgCl showed that the absolute current of the steel decreases with increasing immersion time and that pitting corrosion occurs only at-0.35 V as indicated also by scanning electron microscope images. Electrochemical impedance spectroscopy (EIS) confirmed the results obtained by CPP and CCT that the increase of immersion time from 1 h to 24 h increases both the solution and polarization resistances. Results together were consistent with each other confirming that the corrosion of API X-70 5L pipeline steel in 4.0 wt. % NaCl solution decreas...
Molecules, 2014
In this study, we compared the electrochemical corrosion behavior of a newly fabricated nanocrystalline pure aluminum to another microcrystalline aluminum using various electrochemical techniques in natural Arabian Gulf seawater. The nanocrystalline Al was fabricated using mechanical alloying technique. Cyclic potentiodynamic polarization showed that microcrystalline has lower corrosion current and corrosion rate with higher polarization resistance compared to the nanocrystalline Al. The change of current with time at -550 mV vs. Ag/AgCl revealed that the nanocrystalline Al had higher absolute currents. The scanning electron microscopy images showed that nanocrystalline Al surface was more corroding under the aggressiveness action of the seawater and the applied anodic potential value. This was also confirmed by the electrochemical impedance spectroscopy data, which indicated that the nanocrystalline Al shows lower polarization and solution resistances when compared to the microcrystalline Al. All results were in good agreement showing clearly that the nanocrystalline Al has less corrosion resistance and high corrosion rate in the Arabian Gulf seawater due to the presence of many active centers on its surface.
International Journal of Electrochemical Science
Formation of anodic films was induced through application of potential pulses on the surface of API 5L X52 steel samples immersed in a 0.1 M H 2 SO 4 aqueous solution with different pH set by adding NaOH. The formation mechanism was studied using the step potential technique to produce j-t plots, and the morphology and composition of the resulting films was characterized through SEM and EDX, respectively, and their passivating capacity was also electrochemically evaluated. It is shown that the anodic film was formed, in all cases, by means of nucleation and growth phenomena and that it cannot passivate the corrosion process. Furthermore, the nature of the films formed was also validated from a thermodynamic analysis based on the predominance zones diagram.
Metals
The effect of temperature, time and rotation speed of FT-GTL process water on the corrosion rate of API X-120 carbon steel was investigated. Electrochemical impedance spectroscopy and potentiodynamic polarization techniques were used to determine the carbon steel corrosion rate under temperatures ranging from 293 to 323 K and rotation speed of 0, 500, 1000, 2000 rpm when the immersion time was 0.5, 1, and 2 h. The corrosion rate increased with temperature and rotation speed but decreased with immersion time. SEM, XRD, and XPS analyses of the corroded surfaces confirmed the formation of iron oxide and ferric oxide as the main components of the protective layer.
Corrosion, 2013
The corrosion behavior of API 5L-X65 carbon steel in a carbon dioxide (CO 2)-saturated solution was investigated by electrochemical measurements (polarization curves, Levich plots, and electrochemical impedance spectroscopy) with a rotating disk electrode. Different experimental conditions such as hydrodynamics, immersion time, and temperature were considered. From the polarization curves, it was shown that both the anodic and cathodic current densities decreased as the electrode rotation speed, the immersion time, and the temperature increased. This behavior was in agreement with the impedance results obtained at the corrosion potential. It was shown that the corrosion processes were initially controlled by mass transport but they became under activation control for longer immersion times. Scanning electron microscopy was used to characterize the corrosion products. For short immersion times (2 h and 6 h), the corrosion products mainly deposited on the cathodic sites (pearlitic zones) of the carbon steel surface forming a heterogeneous layer, whereas they covered the whole electrode surface after longer periods (>15 h). At a microscale, localized corrosion, as a result of galvanic coupling between pearlite and ferrite, was also observed.
Materials Sciences and Applications, 2011
The corrosion behavior of 1020C carbon steel samples that had been subjected to oxidizing heat treatment at 550˚C and 675˚C were studied in sodium chloride electrolytes using a 3-electrode electrochemical impedance spectroscopy. Experimental data were used to evaluate the corrosion behavior of the samples while optical microscopy was employed to investigate the surface characteristics of the samples before and after aqueous corrosion. The results showed that while the sample treated at 550˚C revealed an increasing corrosion rate with time, the sample treated at 675˚C indicated a higher initial corrosion rate, but the rate declined gradually over the 4-day experimental period. Optical microscopy revealed significant formation of surface corrosion products on both heat treated samples, but the complex plane diagrams indicated significant capacitive behavior for the heat treated samples relative to the untreated samples.
Materials Research, 2013
X52 and X60 high strength low alloy (HSLA) steels are widely used in the construction of petroleum pipelines. This paper discusses the corrosion resistance of X52 and X60 steels in CO 2 containing saltwater at pH 4.4 and 50 °C. A circulating flow loop system inside an autoclave was used for conducting the experimental work. The rotating impeller speed was 2000 rpm. The corrosion rate was monitored using in situ electrochemical methods such as potentiodynamic sweep, linear polarization resistance, and electrochemical impedance spectroscopy (EIS) methods. Results indicated that the corrosion rate of X60 steel is relatively higher than that of X52 steel.
Applied Surface Science, 2011
The efficiency of a formula containing 2-{(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1yl)methyl]amino}ethanol (tolyltriazole) and decanoic acid as corrosion inhibitor for galvanized steel and electroplating steel in aqueous solution have been determined by electrochemical impedance spectroscopy (EIS) techniques. The experimental data obtained from this method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour in the presence of different concentration of decanoic acid (DA) in the formula was also investigated by EIS. Results obtained reveal that, the formula is a good inhibitor for galvanized steel and electroplating steel in aqueous solution, the better performance was obtained in the case of galvanized steel. The ability of the inhibitor to be adsorbed on the surface was dependent on the nature of metal. X-ray photoelectron spectroscopy surface analysis with inhibitor shows that it's chemisorbed at the galvanized and electroplating steel/aqueous solution interface.
The study of corrosion behaviour api 5l steel in sea water using immersion test method
2020
API 5L steel, a low carbon steel with a high alloy content, is often used as an underwater construction material or oil and gas pipeline. Banten has a wide sea area and has a long coastline where part of the coastline is used for petrochemical industries. There are three coast areas of Banten, namely Bayah Rangkasbitung, Anyer and Merak, that are used for petrochemical industries. Most of those industries use API 5L steel for underwater construction materials and pipes to channel seawater, chemical compounds, gas and oil. Whereas, seawater will greatly affect the lifetime of API 5L construction steel because it can cause corrosion. The purpose of this study is to analyze the corrosion characteristics of API 5L steel affected by the environment of seawater media and the temperature of seawater in accordance with its natural conditions. The samples of API 5L steel were immersed in seawater media with variation of immersion time of 5, 10, 15 Days and variation of immersion temperature of 20 o C, 40 o C, and 60 o C. In this study, a series of tests were carried out, namely immersion test, weight loss test, and SEM test (Scanning Electron Microscopy). The highest corrosion rate on API 5L steel is 0.39 mmpy which belongs to Merak's seawater media in the immersion time of 15 Days and the temperature of 60 o C, while the lowest corrosion rate on the API 5L steel is 0.013 mmpy which belongs to Bayah's seawater media with a time of immersion of 10 Days and a temperature of 20 o C.
Electrochemical corrosion behavior of X80 pipeline steel in a near-neutral pH solution
Mater Corros, 2009
In this work, the electrochemical corrosion behavior of X80 pipeline steel was investigated in a near-neutral pH solution using electrochemical impedance spectroscopy (EIC) and photo-electrochemical (PEC) measurements as well as X-ray photo-electron spectroscopy (XPS) technique. The effects of hydrogencharging and stress were considered. The results show that the steel is in an active dissolution state, and a layer of corrosion product is formed and deposited on the electrode surface, which is subjected to further oxidation to form ferric oxide and hydroxide. Photo-illumination enhances anodic dissolution of the steel when it is under anodic polarization due to destroying of the corrosion product film. When the steel is under cathodic polarization, the cathodic current density decreases upon laser illumination due to the photo-oxidation of hydrogen atoms generated during cathodic reactions, which behaves as an anodic reaction to offset the cathodic current density. Hydrogen-charging and stress decrease the corrosion resistance of the steel and enhance the dissolution rate of the steel.