Atmospheric Corrosion Of Carbon Steel Research Articles

Corrosion of Carbon Steel in a Tropical Marine Environment Enhanced by H2S from Sargassum Seaweed Decomposition

This article aims to investigate the atmospheric corrosion of carbon steel in a marine environment abundant in hydrogen sulfide (H2S) resulting from the decomposition of Sargassum seaweed. To accomplish this, four sites with varying degrees of impact were chosen along the coast of Martinique. The corrosion rates of steel were evaluated through mass loss measurements. After one year of exposure, the corrosion rates were notably high, particularly in atmospheres rich in Cl− ions and H2S, ranging from 107 µm to 983 µm. Complementing these findings, surface and product morphologies were characterized using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). These analyses revealed a significant degradation of the corrosion surface in the most affected atmospheres compared to those unaffected by Sargassum seaweed strandings. Lepidocrocite (γFeOOH) was identified as the predominant product regardless of the exposure atmosphere. However, goethite (αFeOOH) was found to be present in atmospheres most impacted by H2S.

Atmospheric corrosion of carbon steel: Results of one-year exposure in an andean tropical atmosphere in Colombia

In this study was examined the response of carbon steel to atmospheric corrosion after one-year exposure in Valle de Aburrá, a subregion located in northwestern Colombia. The study involved the assessment of material mass loss and corrosion rate, the characterization of atmospheric aggressiveness, and the analysis of the morphology and composition of corrosion products in five different sites. Climatological and meteorological factors were assessed by testing for chloride content, sulfur dioxide levels, and time of wetness (TOW). The analysis of corrosion products was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Based on corrosion rates, two sites exhibited a more aggressive environment, with a corrosivity category of C3, while the remaining sites were categorized as C2. The study confirmed the presence of lepidocrocite and goethite phases on the surface of carbon steel at all test sites. Data analysis revealed that both the TOW and the industrial activity significantly influence the corrosion of this metal.

Physics-Informed, Data-Driven Model for Atmospheric Corrosion of Carbon Steel Using Bayesian Network.

Atmospheric corrosion is a significant challenge faced by the aviation industry as it considerably affects the structural integrity of an aircraft operated for long periods. Therefore, an appropriate corrosion deterioration model is required to predict corrosion problems. However, practical application of the deterioration model is challenging owing to the limited data available for the parameter estimation. Thus, a high uncertainty in prediction is unavoidable. To address these challenges, a method of integrating a physics-based model and the monitoring data on a Bayesian network (BN) is presented herein. Atmospheric corrosion is modeled using the simulation method, and a BN is constructed using GeNie. Moreover, model calibration is performed using the monitoring data collected from aircraft parking areas. The calibration approach is an improvement over existing models as it incorporates actual environmental data, making it more accurate and applicable to real-world scenarios. In conclusion, our research emphasizes the importance of precise corrosion models for predicting and managing atmospheric corrosion on carbon steel. The study results open new avenues for future research, such as the incorporation of additional data sources to further improve the accuracy of corrosion models.

Marine atmospheric corrosion of carbon steel in Mauritius

A geospatial variation of environmental conditions across Mauritius complicates atmospheric corrosion control and prediction. In the current study, field exposures in four distinct locations have given new insights into the marine atmospheric corrosion behavior of carbon steel in the country. Mauritius shows diverse atmospheric aggressivity with corrosion rates affected by both salinity and humidity. An acute thickness loss of 0.5 mm y-1 was associated with a direct spray of marine aerosols while relative humidity was a key factor in increasing the corrosion rate in inland areas.

Life Prediction of Cable Steel Bracket Considering Carbon Steel Corrosion

Replacing the underground cable steel bracket within the service life will increase the maintenance cost, so the life prediction of the cable steel bracket is aroused. The mechanical properties and atmospheric corrosion of carbon steel are the key factors affecting the service life of the bracket. In this paper, a life prediction method of cable steel brackets considering carbon steel corrosion is proposed. First, the mechanical properties of the bracket are analyzed by the finite element model to determine the thickness of the damage. Based on electrochemical corrosion experiments, a life prediction method based on Tafel curve extrapolation is constructed to obtain the corrosion rate; At last, taking the 110 KV underground transmission line of a power grid as an example, the service life of the angle steel bracket of the cable is calculated, which provides a theoretical basis for the selection of steel bracket.

Numerical simulation of carbon steel atmospheric corrosion under varying electrolyte-film thickness and corrosion product porosity

A finite element model is developed to study dynamics of atmospheric corrosion of carbon steel, focusing on the influence of thin electrolyte film thickness under varying corrosion product porosity. Calculations have been done to evaluate the impact of electrolyte film thickness and corrosion product porosity on oxygen diffusion path, and the hindrance effect of corrosion products on the metal surface activity. The time evolution of corrosion current density and controlling steps in the corrosion process are explored. When the corrosion products are loose, oxygen diffusion is the dominant controlling step, and the thicker the electrolyte film, the lower the corrosion rate. When they are dense, the corrosion process is controlled by the mixture of oxygen diffusion and the surface discharge. The oxygen diffusion path is determined only by the corrosion product porosity, and therefore the corrosion rate is not affected by the electrolyte film thickness.

Mechanistic modelling of atmospheric corrosion of carbon steel in Port-Louis by electrochemical characterisation of rust layers

S235 structural steel was exposed for 14 months at six locations in the marine/urban atmosphere of Port-Louis, distinguished by the surrounding bay and mountains. An unusual geospatial variability in terms of chloride deposition rate (7.8–54.3 mg m−2 d−1), SO2 level (1.2–2.4 mg m−2 d−1) and corrosion rate (77.6–189.2 g m−2 y−1) was observed. Electrochemical techniques, supported by mass loss and surface analysis, provide insights into environment-specific corrosion mechanisms, with the occurrence of anomalous diffusion at the aggressive exposure sites. Rust layer corrosion resistances ranged between 4 and 113 Ω cm2.

Marine atmospheric corrosion of carbon steel in the tropical microclimate of Port Louis

AbstractThe atmospheric corrosion performance of S235 carbon steel is assessed when exposed to the tropical/marine aerosol pollutants of Port Louis, Mauritius. Port Louis is situated on the northwest coast and has a distinct microclimate, leading to major atmospheric corrosion concerns. In addition, sulphur dioxide emissions from three heavy oil‐fired power stations complicate corrosion prediction within the region. Mass‐loss analysis shows distinctive corrosion progression behaviours linked to the environmental and geographical variables. The formation of porous surface layers leads to a continuous increase in metal dissolution during the electrochemical process. The surface analysis reveals lepidocrocite and goethite () as the predominant rust phases, with low percentages of magnetite (), akageneite and jarosite . A key insight in the S235 atmospheric corrosion involves two stages: the early rapid corrosion stage followed by a slow stage of linear or power‐law corrosion kinetics due to the formation of stable rust phases.

Long-term corrosion monitoring of carbon steels and environmental correlation analysis via the random forest method

In this work, the atmospheric corrosion of carbon steels was monitored at six different sites (and hence, atmospheric conditions) using Fe/Cu-type atmospheric corrosion monitoring technology over a period of 12 months. After analyzing over 3 million data points, the sensor data were interpretable as the instantaneous corrosion rate, and the atmospheric “corrosivity” for each exposure environment showed highly dynamic changes from the C1 to CX level (according to the ISO 9223 standard). A random forest model was developed to predict the corrosion rate and investigate the impacts of ten “corrosive factors” in dynamic atmospheres. The results reveal rust layer, wind speed, rainfall rate, RH, and chloride concentration, played a significant role in the corrosion process.

Prediction of tempo-spatial patterns and exceedance probabilities of atmospheric corrosion of Q235 carbon steel across China.

To reduce the losses caused by the atmospheric corrosion of carbon steels, it is important to establish a prediction model to determine the corrosion rate of carbon steels in natural environments. In this study, a prediction model of atmospheric corrosion of Q235 carbon steel (PMACC-Q235) in China was established by coupling the mean impact value algorithm and back propagation artificial neural network. Tempo-spatial patterns of corrosion rates in five long-exposure time categories across China were analyzed. Ten main factors affecting the atmospheric corrosion of Q235 were identified. The corrosion rates in a single year were similar (approximately 30 μm/a) and larger than those for 2 (25.30 μm/a) and 3 years (21.66 μm/a). The spatial corrosion rates in the northwestern areas were primarily lower than those in southeastern coastal areas. This could be influenced by climatic factors, such as temperature, humidity, and precipitation. All corrosion rates reached the C2 level (>1.3 μm/a), and there was some possibility that they reached higher corrosion levels. The largest probability for the C3 level in all periods was an average of 0.91, and that for the C4 level was 0.83. Spatially, higher probabilities were mainly located in the southern area, especially in Hainan, located in the south and surrounded by sea. Corrosion rates largely varied among climatic zones, and mean corrosion rates in the tropical monsoon climate zone were the largest (average of three periods 33.39 μm/a). SO2 and soluble-dust fall had the largest impact on the variations in the corrosion rates among different climatic zones.

A Field Study of Atmospheric Corrosion of Carbon Steel after Short Exposure in Pelabuhan Ratu, West Java Province, Indonesia

The investigation of atmospheric corrosion of mild carbon steel as representative of offshore infrastructure has been carried out in the marine tropical of Pelabuhan Ratu, West Java, Indonesia. They are exposed up to 76 days of periods, and their corrosion rates are determined according to ASTM G1-03. The surface morphology, the elemental compositions and compounds were observed using a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The environmental parameters of the test site are monitored during exposure, such as air temperature, relative humidity (RH), airborne salinity and dew temperature. Based on the results, the corrosion rates of steels were 2.79 and 2.8 mpy within the 27 and 76 days exposures, respectively. The presence of chloride deposition on the surface of steel can increase the severity of corrosion. Moreover, the detrimental effect of chloride was observed in rust product, which was covered by an oxygen element. The main phases of rust products present were magnetite (Fe3O4) and hematite (α-Fe2O3.H2O). Several cracks were observed in the rust layer, which tended to exfoliate and lose adherence and protectiveness from further corrosion attack. HIGHLIGHTS The presence of chloride deposition on the surface of steel can increase the severity of corrosion. The severity of corrosion attack mainly depends on the exposure time and some climatic parameters, such as relative humidity (RH), air temperature and chloride airborne. The uniform distribution of the chloride tends to increase the production of ferrous chloride in high RH condition and the aqueous layer deposited on carbon steel. There are two phases on corroded carbon steel such as hematite (α-Fe2O3.H2O) and Magnetite (Fe3O4) after exposure GRAPHICAL ABSTRACT

Modeling and Simulation of Atmospheric Corrosion of Carbon Steel Considering Environmental Factor

Modeling and Simulation of Atmospheric Corrosion of Carbon Steel Considering Environmental Factor

Effects of Dissolved Oxygen Concentration in Electrolyte Film on Atmospheric Corrosion of Carbon Steel

Steel is used for infrastructures such as bridges due to its superior mechanical properties as well as low cost. However, atmospheric corrosion of steel causes the deterioration of strength of the steel. As corrosion rate of steel in atmospheric environment strongly depends on the oxygen reduction reaction on rusts of the steel as well as the reduction of the rusts, effects of structure and properties of rust have been examined. In addition, as atmospheric corrosion proceeds under an electrolyte film, the oxygen reduction rate is not necessarily diffusion-limited, that is, the corrosion behavior is reported to be different form that in bulk aqueous electrolyte. Furthermore, steels used for bridges are used for the most of their life time with the presence of rust layer on the steels. Therefore, investigations on the corrosion behavior of rusted steel under an electrolyte film are required to assess the corrosion life time of bridges. The present work aims at revealing the dissolved oxygen concentration in rust layers under an electrolyte film by simultaneous measurements of electrochemical parameters and the dissolved oxygen concentration in an electrolyte film on rusted steel.

Evaluation of 4-Year Atmospheric Corrosion of Carbon Steel, Aluminum, Copper and Zinc in a Coastal Military Airport in Greece

Atmospheric corrosion seriously affects the working life of construction metals. The quantitative knowledge of the corrosion effects helps the maintenance and the materials’ logistics. In this work, in a military airport located by the sea, the corrosion damage equations of carbon steel, aluminum, zinc and copper are determined after outdoor exposure for four years. Exposure started in 2014, at two different periods of the year, in summer and in winter, for all cases. Weight loss measurements were performed as well as characterization of the exposed metal coupon surfaces by microscopy: optical, electron and atomic force, by X-ray diffraction and Fourier Transform Infrared Spectroscopy. Atmospheric conditions and pollutants were also evaluated. The derived corrosion equations of all tested metals for the exposure have been employed for the 30-year projection of expected corrosion. A parallel 12-month exposure of steel and aluminum—the most common airport metals—have been evaluated for five consequent years to designate the rating of the airport, according to ISO and ASTM Standards. The results showed that there is not a good correlation between the predictions of the Corrosion Damage Algorithm and the Europe Corrosion Map and the actual measurements on steel and aluminum at the site.

Towards understanding and prediction of atmospheric corrosion of an Fe/Cu corrosion sensor via machine learning

The atmospheric corrosion of carbon steel was monitored by a Fe/Cu type galvanic corrosion sensor for 34 days. Using a random forest (RF)-based machine learning approach, the impacts of relative humidity, temperature and rainfall were identified to be higher than those of airborne particles, sulfur dioxide, nitrogen dioxide, carbon monoxide and ozone on the initial atmospheric corrosion. The RF model demonstrated higher accuracy than artificial neural network (ANN) and support vector regression (SVR) models in predicting instantaneous atmospheric corrosion. The model accuracy can be further improved after taking into consideration of the significant effect of rust formation on the sensor.

Atmospheric corrosion of carbon steels in tropical and subtropical climates in Southern China

AbstractQ235 and Q345 carbon steels were exposed for up to 24 months at three test sites of tropical and subtropical climate. The atmospheric corrosion kinetics of Q235 and Q345 was studied by weight‐loss measurement. The results show that the ranking of the atmospheric corrosivity from weak to strong of the three test sites is Xishuangbanna, Guangzhou, and Wanning. The kinetics of the atmospheric corrosion process presents two stages with an accelerated second stage in marine environments of high chloride ion content and high relative humidity, whereas no second stage appears in the kinetics curves in rural and industrial urban environments. The corrosion acceleration stage in the marine environment of the Wanning site is attributed mainly to the high chloride ion concentration and loose rust layer structure.

Vapor phase assembly of urea–amine compounds and their protection against the atmospheric corrosion of carbon steel

Two kinds of polyamine compounds, bis-cyclohexylaminoethylurea (BCAU) and monocyclohexylaminoethylurea (MCAU), are synthesized via Mannich reaction. The anticorrosion films on carbon steel surface are prepared by the vapor phase assembly method. After 72 h volatilization at 50°C, the mass-loss for BCAU and MCAU in the closed space are 1.13% and 1.45%. The volatile-inhibiting sieve (VIS) test, the volatile-inhibiting ability test and the electrochemical impedance spectroscopy measurement are used to compare the prevention of the atmospheric corrosion by the assembly film. BCAU and MCAU have 92.44% and 87.56% inhibition efficiency for carbon steel in VIS test. On the basis of theoretical calculation and surface analysis, the protective film structures on carbon surface from the vapor phase assembly are proposed.

An Early Stopping-Based Artificial Neural Network Model for Atmospheric Corrosion Prediction of Carbon Steel

The optimization of network topologies to retain the generalization ability by deciding when to stop overtraining an artificial neural network (ANN) is an existing vital challenge in ANN prediction works. The larger the dataset the ANN is trained with, the better generalization the prediction can give. In this paper, a large dataset of atmospheric corrosion data of carbon steel compiled from several resources is used to train and test a multilayer backpropagation ANN model as well as two conventional corrosion prediction models (linear and Klinesmith models). Unlike previous related works, a grid searchbased hyperparameter tuning is performed to develop multiple hyperparameter combinations (network topologies) to train multiple ANNs with mini-batch stochastic gradient descent optimization algorithm to facilitate the training of a large dataset. After that, one selection strategy for the optimal hyperparameter combination is applied by an early stopping method to guarantee the generalization ability of the optimal network model. The correlation coefficients (R) of the ANN model can explain about 80% (more than 75%) of the variance of atmospheric corrosion of carbon steel, and the root mean square errors (RMSE) of three models show that the ANN model gives a better performance than the other two models with acceptable generalization. The influence of input parameters on the output is highlighted by using the fuzzy curve analysis method. The result reveals that TOW, Cl- and SO2 are the most important atmospheric chemical variables, which have a well-known nonlinear relationship with atmospheric corrosion.

Outdoor atmospheric corrosion of carbon steel and weathering steel exposed to the tropical‐coastal climate of Thailand

AbstractThis study focuses on atmospheric corrosion of carbon steel and weathering steel exposed at two different locations with dissimilar meteorological parameters and airborne pollutants in Thailand. The samples are subjected to an outdoor atmosphere for up to 36 months at Rayong, close to the Gulf of Thailand, and Phangnga, near the Andaman Sea. Thickness loss (µm), corrosion rate (µm/year) together with corrosion product morphology and composition are systematically analyzed using X‐ray diffraction and a scanning electron microscope. Corrosion resistance of the tested steels exposed at both locations is discussed based on the above‐mentioned parameters and calculated corrosion kinetics. The results indicate that the total time of wetness, amount of rainfall and chloride deposition rate play an important role in corrosion behavior of the tested steels. Alloying elements, copper, chromium and nickel, are shown to improve corrosion resistance of the samples when exposed at the location with a higher chloride concentration.

Atmospheric corrosion study in a harbor located in a tropical island

Atmospheric corrosion level in tropical coastal zones is usually very significant. Corrosion control and preservation of infrastructure in these regions is very important to increase durability. Atmospheric corrosion of carbon steel, copper, galvanized steel, and aluminum was evaluated in a coastal industrial port zone located in a tropical island during 1 year. Samples were exposed at seven outdoor corrosion sites located at different distances from the sea. Main atmospheric pollutants, relative humidity, and air temperature were monitored during the exposure time. The existence of a combination between two of the most aggressive atmosphere types was determined (coastal‐industrial and industrial‐coastal). Changes in RH and temperature influenced significantly the chloride deposition. A new statistical model to explain the influence of time of exposure for all metals tested was developed. A possible antagonist effect between pollutants on corrosion may be possible. Acceleration of corrosion rate vs time is observed in the site close to the shoreline. Significant differences between corrosivity categories determined and those calculated by ISO standard dose response functions were found. The narrow entrance of the harbor with low movement of the inner water causes a decrease in salinity in the port zone.