Corrosion Process Of Steel Research Articles

Heptanoic acid adsorption on grafted palygorskite and its application as controlled-release corrosion inhibitor of steel

This study deals with the anchoring of heptanoic acid (HC7) as a corrosion inhibitor to palygorskite clay mineral originated from High Atlas of Marrakech (Morocco) beforehand grafted with 3-aminopropyltriethoxysilane (APTES) entities. Physicochemical characterizations (XRD, FTIR, TG-MS, zeta potential measurements) confirmed the success of the APTES-grafting to silanol sites of palygorskite fibers edges and the heptanoate anions bonding to terminal NH3+ sites of grafted-APTES. Then, full-factorial design allowed optimizing the conditions of heptanoate adsorption. Preliminary electrochemical measurements revealed that functionalized grafted palygorskite (C7-APTES–Pal) can progressively release the heptanoate corrosion inhibitor in 0.1 M NaCl solution to inhibit the steel corrosion processes.

The corrosion process of P-110 steel in stimulation fluids used in the oil industry

The use of chelating agents in the oil well stimulation processes has been proposed as an alternative to the acid treatment when the formations damage do not allow the usage of strong chemical attack. However, this procedure can arouse the corrosion of the steel used in the infrastructure of the oil production. In this study, the corrosion kinetics of the P-110 steel in ethylenediaminetetraacetic acid (EDTA)-based fluids is assessed under different conditions of evaluation. Linear polarization was performed in different hydrodynamic regimes and at different temperatures, in order to evaluate the kinetic of steel corrosion. The working electrolyte solution comprises 10% disodium EDTA and 20% tetrasodium EDTA. The increase of temperature from 25 to 80°C in both electrolytes increments the corrosion rate of steel in at least one order of magnitude; particularly in EDTA-Na2 solutions. Corrosion rates of 0.29x101 and 1.67x102 mm.y-1 were measured at 25 and 80°C, respectively. The hydrodynamic regime plays an important role in the corrosion of steel only in the disodium solution, where corrosion rates were increased at higher rotation speeds of the electrode. The cathodic depolarization effect is more important in the EDTA-Na2 than in the EDTA-Na4 solution, making it more corrosive.

Steel corrosion and corrosion-induced cracking in recycled aggregate concrete

This study investigated four reinforced concrete mixtures with different replacement percentages of recycled coarse aggregate (RA). The corrosion rate was measured using an electrochemical workstation, and the corrosion-induced cracks on the concrete surface were observed using digital microscopy. The results show that the use of RA introduces more interfaces in concrete, which accelerates the steel corrosion process and corrosion-induced crack propagation in concrete cover. However, steel corrosion and the corrosion-induced cracking process in concrete are not significantly influenced by replacing a small amount (33% in the study) of coarse aggregate with RA.

Corrosion Behavior of Low Carbon Steel Exposed to Different Soils

In this work the corrosion process of X52 pipeline steel in three different Mexican soils was studied. Sandy, clay and marshy soils were studied in function of moisture content. The results were related to the different stages (dry and rainy) that underground pipelines suffer during the season of the year. The electrochemical evaluations were carried out at different periods of time. The soils evaluated have different water retention and each soil has a moisture value in which the corrosion process is more active. However, this value for the marshy soil only belongs to the maximum value of moisture. The analysis of results, suggested that the corrosion phenomenon is different for each soil. The electrochemical results shown that, there was a moisture value on each type of soil that it accelerates the corrosion phenomenon. So, there is moisture content where the corrosion rate is maximum (12.7, 31.4 and 53.1 wt% H2O, for the sandy, clay and marshy soils, respectively), obtaining values of 0.256, 0.294 and 0.383 mm/year. Furthermore, this paper propose the use of the electrochemical techniques as a complementary tool for the analysis of the cathodic protection in underground pipelines at different stages of season of the year, due to the voltage variations in different types of soils and different moisture content.

Electrochemical study on the corrosion of rusted carbon steel in dilute NaCl solutions

Purpose – The purpose of this study was to investigate the corrosion of rusted carbon steel in dilute NaCl solution, with the purpose of exploring the effect of the rust layer on metal corrosion and establishing a corrosion model for rusted iron. Design/methodology/approach – The corrosion behavior of rusted carbon steel in dilute NaCl solution was studied by means of weight-loss determinations, scanning electron microscopy, Raman spectrometry and electrochemical techniques. Findings – The results indicated that carbon steel had a similar corrosion behavior in all three NaCl solutions. The iron rust, which consisted of a thin γ-FeOOH layer and a thick Fe3O4 layer, can facilitate the corrosion process of carbon steel via reduction of γ-FeOOH and the large area cathode of Fe3O4. Hence, the corrosion rate of carbon steel was accelerated significantly and finally was determined by the limiting diffusion rate of oxygen. Originality/value – A corrosion model of rusted carbon steel was established, suggesting that iron rust formed in all slightly acidic waters with low alkalinity probably promotes the corrosion of carbon steel. Anti-corrosion measures for iron in this type of solution, such as desalination water, should be aimed to reduce the promotional effect of the rust layer on metal corrosion.

Corrosion behavior of X65 carbon steel in simulated oilfield produced water

Corrosion behavior of X65 steel in simulated oilfield water was studied by weight loss, polarization curve, electrochemical impedance spectroscopy, scanning electron microscope, and X‐ray diffraction methods. Effects of temperature, acetic acid concentration, and CO2 partial pressure on the corrosion behavior were discussed. Results showed that the corrosion rate increased with the increasing of temperature, acetic acid concentration, and CO2 partial pressure. High temperature favored the formation of FeCO3; the addition of acetic acid could speed hydrogen depolarization, but the more acetic acid could remove FeCO3 layer, CO2 mainly influenced the cathodic reaction, appearing limiting diffusive current density. Acetic acid and CO2 had a synergistic effect on the corrosion process of X65 carbon steel in simulated oilfield produced water.

Effects of Carbon Content and Microstructure on Corrosion Property of New Developed Steels in Acidic Salt Solutions

New steels with different carbon contents were self-developed by thermo-mechanical controlled processing. The effects of the carbon content and the microstructure on the corrosion properties of new steels were investigated by immersion test and SEM. The results indicated that the ferrite phase (both the proeutectoid and eutectoid ferrite) dissolved preferentially. Cementite reserved and accumulated on the surface. As carbon content increased, the content of ferrite decreased and cathode/anode area ratio increased. Therefore, the corrosion rate of new steels increased from 0.30 to 0.90 mm/years when the carbon content rose from 0.05 to 0.13 wt%. The corrosion process of new steels was studied using electrochemical impedance spectroscopy experiments during 72 h. It indicated that the impedance modulus |Z|0.01 Hz of the new steels reduces with the increase of the immersion time. While the corrosion process of the new steel with 0.11 wt% C developed faster than that with 0.07 wt% C, although their |Z|0.01 Hz was similar at the initial stage.

Steel corrosion assessment by electrochemical impedance on metakaolin blended mortars

Since Corrosion of reinforcing steel in concrete is the cause of major economic losses, Portland cement has been traditionally replaced by cements blended with pozzalanic materials, most of which have been found to reduce the corrosion of steel. This paper shows the results of an experimental research aimed to investigate the corrosion of reinforcement in mortar using electrochemical impedance spectroscopy (EIS). For this, concrete laboratory samples containing a 0.0055 m steel bar and prepared with just ordinary Portland cement (OPC) and metakaolin at a replacement level of 20% were analyzed. In order to accelerate the steel corrosion process, all the samples were kept in a 3% NaCl solution and a constant anodic electrical potential was applied. Variations in the water to cementitious material ratio (0.5 and 0.6) and metakaolin proportion were analyzed, while the cementitious material to sand ratio was kept constant at 1:2.25 in all of the specimens. The results showed a reduction in corrosion rates when metakaolin was used as a blending admixture, especially at water to cementitious material ratio of 0.5.

Zinc-free varnishes and zinc-rich paints modified with ionic liquids

The corrosion protection of a steel substrate using zinc-rich epoxy–alkyd paints (ZRPs) modified with either 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF6) or 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyrrTFSI) has been investigated. Additionally, the influence of ionic liquids (ILs) on the corrosion process of uncoated steel and zinc as well as on electrical features of zinc-free varnishes has been evaluated. The pyrrolidinium IL significantly reduces the corrosion rates of steel and zinc but the ZRPs with HMIMPF6 offer better cathodic protection of steel than unmodified ZRP and ZRPs with BMPyrrTFSI. The electrical conductivity of IL is not critical for the protective features of ZRP.

Effect of W, Mo, and Ti on the Corrosion Behavior of Low-Alloy Steel in Sulfuric Acid

The effects of W (0.05 wt% W), Mo (0.05 wt% Mo), and Ti (0.05 wt% Ti) addition on the corrosion resistance of low-alloy steel used in flue gas desulfurization systems were examined using electrochemical measurements in a 10 wt% sulfuric acid (H2SO4) solution. The corrosion rate increased in the following order: W steel < Mo steel << Ti steel. The surface analysis indicated that the type and quantity of inclusions by steel are as follows: W steel (manganese sulfide [MnS]) < Mo steel (MnS, molybdenum disulfide [MoS2]) << Ti steel (MoS2, titanium sulfide [TiS]). The corrosion rate was influenced by sulfide inclusions in the steels. In particular, the corrosion rate of Ti-containing steel was the highest due to a large number of TiS inclusions formed during the steel manufacturing or corrosion processes.

Effect of ions on carbon steel corrosion in cooling systems with reclaimed wastewater as the alternative makeup water

The corrosion behavior of carbon steel in cooling systems using reclaimed wastewater as the makeup water was investigated. Effect of typical ions (Cl−, SO42-, NO3-, and NH4+) on the corrosion of carbon steel in cooling systems was evaluated. The electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy were used to measure the corrosion rate and analyze the corrosion processes. Also scanning electron microscopy, Fourier transform infrared spectrometer and energy dispersive spectroscopy were applied to surface analysis. Among the examined ions, Cl− had the highest influence on the corrosion of the carbon steel, followed by SO42-, NO3-, and NH4+. During cooling cycle, the corrosion process of carbon steel was controlled by cathodic reaction. Corrosion rate increased at the initial stage and then decreased thereafter due to the combined effect of ions and corrosion layer. The ions accelerated the initial corrosion of carbon steel in cooling system, while the corrosion layer hindered this effect. The corrosion layer was dense, uniform, and made up of crystalline particles and the main corrosion products were ferric hydroxides and iron oxide.

Effects of Different Ions on the Corrosion Behavior of SM 80SS Tubing Steel in CO<sub>2</sub>/H<sub>2</sub>S Containing Aqueous Solution

As an attempt to contribute to the understanding of the corrosion processes of anti-sulfur steel in CO2 and H2S containing environment with different species, the corrosion behavior of SM 80SS tubing steel immersed in CO2 and H2S containing solution was analyzed in this work. To determine the corrosion behavior of SM80SS steel, the linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) techniques were used, as well as weight loss test and surface analysis. The results showed that the presence of Cl- quickened the anodic dissolution processes and rapidly increased the corrosion rate of SM 80SS steel, and that the addition of Ca2+ and Mg2+ reduced corrosion rate. The corrosion processes of SM 80SS steel were controlled by the electrochemical reaction in the initial period and then converted to be controlled by electrochemical and activation reaction with increasing Cl-. Keywords: SM 80SS tubing steel; CO2/H2S corrosion; EIS; Chloride; Ca2+ + Mg2+

Study on Corrosion Electrochemical Behavior of X42 and 16Mn Steel in Seawater

In order to study the corrosion characteristics of 16Mn and X42 steel in natural seawater, the indoor contrast corrosion experiments are carried out in seawater by electrochemical method. Tafel polarization curves and electrochemical impedance spectroscopy (EIS) techniques are employed to investigate the corrosion electrochemical behavior of 16Mn and X42 steel, which are acquired by electrochemical workstation. The results of polarization curves and EIS reveal the respective corrosion rules of 16Mn and X42 steel in natural seawater. At last, the different influence of corrosion scale on the corrosion process of 16Mn and X42 steel is analyzed contrastively.

Acoustic Emission Monitoring of Low Carbon Steel Corrosion inside and outside the Comparative Study

This paper applied acoustic emission technology, monitoring low carbon steel uniform corrosion process, obtained low carbon steel corrosion acoustic emission signal in the process of uniform corrosion, And analyzed acoustic emission signal characteristics of the low carbon steel corrosion process applied the method combining characteristic parameters with wavelet packet transform, in the meantime combined the detection data of storage tank, Contrast acoustic emission signal characteristics of low carbon steel corrosion in experiment conditions and acoustic emission signal characteristics of storage tank corrosion in actual conditions, the result provides reference for acoustic emission research of low carbon steel uniform corrosion process and tanks online acoustic emission testing.

Metal corrosion by aerobic bacteria isolated from stimulated corrosion systems: Effects of additional nitrate sources

Many microorganisms are reported to influence the corrosive behaviour of mild steel and stainless steel in different habitats. In this study, 40 bacterial strains were isolated from corroded mild steel and stainless steel coupons in the nitrate supplemented environments. The corrosion abilities of the isolates against the mild steel and stainless steel coupons were tested with or without additional nitrate sources. The presence of bacterial isolates alone stimulated the corrosion of mild steel coupons. Most of the bio-corrosion processes of mild steel coupons were mitigated by adding nitrate supplement with bacterial isolates. The effects of bacterial isolates and additional nitrogen sources on corrosion of stainless steels were varied. Not all bacterial isolates stimulated the corrosion on stainless steel during the study period. Unlike the effects on mild steel coupons, additional NaNO3 might stimulate, retard the corrosion rate by the bacterial isolates or have limited effects. Similar results were obtained when NH4NO3 was used. Phylogenetic analysis demonstrated that all isolates were closely related. The majority of the bacterial isolates from corroded metal coupons were identified as Bacillus species. Others were identified as Pseudomonas sp., Marinobacter sp., and Halomonas species. The results prove that the isolated aerobic microorganisms do play a role in the corrosion process of stainless and mild steel. Adding additional nitrate sources might be a tool to mitigate corrosion of mild steel which was stimulated by the presence of bacteria. However, to prevent the corrosion of stainless steels, it might need a trial and errors approach in each case.

Relationship between concrete resistivity and corrosion rate – A literature review

The process of reinforcement corrosion in concrete is partially controlled by the transport of ions through the concrete microstructure. Ions are charged and the ability of a material to withstand transfer of charge is dependent upon the electrical resistivity. Thus, a connection could be expected between the corrosion process of steel embedded in concrete and the electrical resistivity of concrete. This paper reviews research concerning the relationship between corrosion rate and concrete resistivity. Overall, there exists an inverse proportional correlation between the parameters. However, the dependency varies between studies and one single relationship cannot be established between corrosion rate and resistivity. To address the variation, the article reviews and evaluates the influence of factors including the experimental setup, the concrete mix design and the cause of corrosion.

Evaluation of Zinc Rich Paint (ZRP) Efficiency on Mild Steel in Seashore Environment

Exposure to humidity and salinity in atmosphere will accelerate the corrosion process of steel. Corrosion of metallic surfaces can be reduced or controlled by addition of chemical compounds to corrodent. Zinc is one of the most important components for commercial application in the corrosion protection of steel, for which it is extensively employed to coat or galvanize ferrous metallic products. In this paper is focused with directly on efficiency of ZRP coating applied on steel substrate under NaCl solution as artificial seashore environment by using Open Circuit Potential (OCP) measurements and Electrochemical Impedance Spectroscopy (EIS).

INFLUENCE OF MICROSTRUCTURE OF AH32 CORROSION RESISTANT STEEL ON CORROSION BEHAVIOR

International martime organization (IMO) has approved and considered corrosion resistant steel as the only alternative for anti-corrosion coating since May 2010. The implementation of the standard will have a profound impact on ship building, steel, shipping and other industries. At present, Japan has a relatively mature technology, South Korea has completed the pre-development work, while China has only carried out some preliminary studies. If the technology is blocked, a large number of steel needs to be imported which would push up the cost of construction of the shipbuilding industry, and has a direct impact on the orders of shipping enterprises. The amount of steel for cargo oil tank in China is more than two million tons each year, and therefore, the localization of research and application of corrosion resistant steel for cargo oil tanks has become an urgent task. The impact of microstructure of the existing shipbuilding steel on corrosion behavior in simulated corrosion environment is studied based on the standard in this paper to develop our own corrosion resistant steel. According to the standard, immersion test was used to measure the corrosion process of AH32 corrosion resistant steel in the bottom simulated environment of cargo oil tanks. Using gravimetric measurement, electrochemical polarization and impedance methods, scanning electron microscopy and electron probe et al, the influence of microstructure of AH32 corrosion resistant steel on its corrosion behav- iors was analysed. The experimental results showed that: during the test simulating the corrosion of the

Crevice Corrosion Behaviors of X52 Carbon Steel in Chloride Containing Solutions

The crevice corrosion behaviors of X52 carbon steel in two typical Cl--containing solutions were investigated by electrochemical noise and electrochemical impedance spectroscopy. Results show that oxygen concentration difference leads to the coupled current in NaCl + NaHCO3 solution while HAc concentration difference causes the coupled current in NaCl solution saturated with CO2 in the presence of HAc. There exists an apparent incubation stage during the crevice corrosion process of X52 carbon steel in the former. However, no obvious incubation period of crevice corrosion can be observed in the latter. Micrography shows that the crevice corrosion occurs indeed and the corrosion inside the crevice is not uniform.

The influence of thin benzoate-doped polyaniline coatings on corrosion protection of mild steel in different environments

The corrosion process of mild steel in the presence of benzoate-doped polyaniline coatings exposed to different environments (3% NaCl, atmosphere, and the Sahara sand) has been investigated. This system was also tested for cathodic protection and it has proven more efficient comparing to mild steel alone. Possible mechanisms of the corrosion protection of mild steel in the presence of a polyaniline-based coating in different corrosion media were also proposed.