scholarly journals Some Clarifications Regarding Literature on Atmospheric Corrosion of Weathering Steels

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
I. Díaz ◽  
H. Cano ◽  
B. Chico ◽  
D. de la Fuente ◽  
M. Morcillo
Keyword(s):  
Corrosion Rate ◽  
Environmental Conditions ◽  
Atmospheric Corrosion ◽  
Research Work ◽  
Rust Layer ◽  
Morphology And Structure ◽  
Time Of Wetness ◽  
Best Fit

Extensive research work has thrown light on the requisites for a protective rust layer to form on weathering steels (WSs) in the atmosphere, one of the most important is the existence of wet/dry cycling. However, the abundant literature on WS behaviour in different atmospheres can sometimes be confusing and lacks clear criteria regarding certain aspects that are addressed in the present paper. What corrosion models best fit the obtained data? How long does it take for the rust layer to stabilize? What is the morphology and structure of the protective rust layer? What is an acceptable corrosion rate for unpainted WS? What are the guideline environmental conditions, time of wetness (TOW), SO2, and Cl−, for unpainted WS? The paper makes a review of the bibliography on this issue.

A Study on the Weatherability of Weathering Steel after Atmospheric Corrosion

2012 ◽  
Vol 479-481 ◽  
pp. 574-577
Author(s):  
Zhi Fen Wang ◽  
Jian Rong Liu ◽  
Li Xin Wu ◽  
Hai E Huang ◽  
Qian Xue Zhou
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Atmospheric Corrosion ◽  
Alloying Elements ◽  
Weathering Steel ◽  
Rust Layer ◽  
Copper Chromium

The weatherability of a weathering steel W450QN was compared with a carbon steel Q345 after 5 years atmospheric corrosion. The results indicated that the corrosion resistance was better for W450QN than Q345 based on the corrosion rate. The characteristics of the rust layers indicated the rust layer on W450QN was denser and thicker than that of Q345. The rust layers were mainly composed of goethite (α-FeOOH) with a few of lepidocrocite (γ-FeOOH). W450QN had better weatherability attributed to the alloying elements of copper, chromium and phosphorus enriched in the rust layer.

Corrosion behaviors of weathering steel 09CuPCrNi welded joints in simulated marine atmospheric environment

2016 ◽  
Vol 63 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Lihua Gong ◽  
Qing Xing ◽  
Huihuang Wang
Keyword(s):  
Corrosion Rate ◽  
Base Metal ◽  
Welded Joints ◽  
Atmospheric Corrosion ◽  
Atmospheric Environment ◽  
Weathering Steel ◽  
Low Alloy Steel ◽  
Rust Layer ◽  
Content Type ◽  
Corrosion Behaviors

Purpose The purpose of this paper is to investigate the effect of welding procedure on the corrosion behaviors of weathering steel 09CuPCrNi in marine atmospheric environment. The corrosion processes of weathering steel 09CuPCrNi and its welded joints in marine atmospheric environment were simulated by a salt spray dry-wet test. Design/methodology/approach The corrosion behaviors of the base metal and the welded joints at corrosion times of 2, 4, 8, 12, 24 weeks were investigated by weight loss test, electrochemical techniques, scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA). The corrosion rates, as well as the morphologies and electrochemical characteristics of corrosion products, the distribution of major alloying elements in rust layer were obtained. The influence of welding on the atmospheric corrosion of 09CuPCrNi was studied. Findings The results indicate that the corrosion rate of the 09CuPCrNi welded joints decreases gradually with the corrosion time, and the major alloying elements are enriched in the inner rust layer, which are similar to that of the base metal. In the early stage during the corrosion process, the welded joints with inhomogeneous structure show the poorer corrosion resistance than that of the base metal. However, it looks the opposite way around in the late corrosion stage, when the uniform corrosion products with even thickness of the base metal tend to detach from the substrate easier and earlier and resulting in cracks, which increase the corrosion rate comparatively with that of the welded joints. Originality/value 09CuPCrNi low alloy steel is a kind of typical weathering steel developed in China which is similar to Corten A developed by USA. Nowadays, 09CuPCrNi low alloy steel is widely adopted in many fields which require welding processes. In the past years, the research of weathering steel welded joints was mainly concentrated on the strength, toughness and weldability. Less work has been done to investigate the difference of corrosion evolution and characteristics between the base metal and its welded joints. Thus, the main objective of the present work was to analyze the influence of welding on the atmospheric corrosion.

scholarly journals A Machine Learning-Based Model for Predicting Atmospheric Corrosion Rate of Carbon Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Ngoc-Long Tran ◽  
Trong-Ha Nguyen ◽  
Van-Tien Phan ◽  
Duy-Duan Nguyen
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Atmospheric Corrosion ◽  
Chloride Ion ◽  
Tropical Climate ◽  
Ion Concentration ◽  
Ann Model ◽  
Climate Conditions ◽  
Average Temperature ◽  
Time Of Wetness

The purpose of this study is to develop a practical artificial neural network (ANN) model for predicting the atmospheric corrosion rate of carbon steel. A set of 240 data samples, which are collected from the experimental results of atmospheric corrosion in tropical climate conditions, are utilized to develop the ANN model. Accordingly, seven meteorological and chemical factors of corrosion, namely, the average temperature, the average relative humidity, the total rainfall, the time of wetness, the hours of sunshine, the average chloride ion concentration, and the average sulfur dioxide deposition rate, are used as input variables for the ANN model. Meanwhile, the atmospheric corrosion rate of carbon steel is considered as the output variable. An optimal ANN model with a high coefficient of determination of 0.999 and a small root mean square error of 0.281 mg/m2.month is retained to predict the corrosion rate. Moreover, the sensitivity analysis shows that the rainfall and hours of sunshine are the most influential parameters on predicting the atmospheric corrosion rate, whereas the average chloride ion concentration, the average temperature, and the time of wetness are less sensitive to the atmospheric corrosion rate. An ANN-based formula, which accommodates all input parameters, is thereafter proposed to estimate the atmospheric corrosion rate of carbon steel. Finally, a graphical user interface is developed for calculating the atmospheric corrosion rate of carbon steel in tropical climate conditions.

scholarly journals Effect of Oxide Scale Microstructure on Atmospheric Corrosion Behavior of Hot Rolled Steel Strip

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 517
Author(s):  
Bin Sun ◽  
Lei Cheng ◽  
Chong-Yang Du ◽  
Jing-Ke Zhang ◽  
Yong-Quan He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Scale ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Corrosion Test ◽  
Atmospheric Corrosion ◽  
Corrosion Mechanism ◽  
Type I ◽  
Rust Layer ◽  
Hot Rolled

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.

scholarly journals The Effect of Salt Solutions and Absorption Cycles in the Capillary and Drying Coefficient of Red Brick Samples with Different Joints

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
A. S. Guimarães ◽  
J. M. P. Q. Delgado ◽  
V. P. de Freitas ◽  
A. P. Albuquerque
Keyword(s):  
Molecular Diffusion ◽  
Research Work ◽  
Sodium Sulphate ◽  
Capillary Absorption ◽  
Material Decomposition ◽  
Salt Solutions ◽  
Partial Immersion ◽  
First Order Kinetics ◽  
Building Components ◽  
Best Fit

Rising damp can reduce building’s aesthetical value, comfort, and health mark when combined with the existence of soluble salts in the building components and in the ground water can even lead to material decomposition and compromise its structural performance. This research work intended to study the effect of different absorption cycles of two saturated solutions of sodium sulphate and potassium chloride in the capillary absorption curves obtained through the partial immersion of red brick samples without and with different joints. The results revealed significant differences in the capillary coefficients obtained when samples were tested with salt solutions. In the end of this paper an evaluation of the drying kinetics was presented for all the tested samples. Four different first-order kinetics models, available in the literature, were adjusted to describe the drying process and the results point that the Page and Logarithmic models allow the best fit. The apparent molecular diffusion coefficient for solid red brick samples saturated with different solutions and joints was also estimated.

Research on Prediction of Carbon Steel in SO2 Atmospheric Corrosion Using Grey Model

2014 ◽  
Vol 507 ◽  
pp. 258-262
Author(s):  
Ping Wang ◽  
Zhao Hui Yin ◽  
Han Tao Ren ◽  
Song Xu
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Prediction Model ◽  
Relative Error ◽  
Atmospheric Corrosion ◽  
Grey Model ◽  
Fitting Accuracy

The rate of carbon steel in SO2 Atmospheric Corrosion was modeled by grey model GM (1, 1). The accuracy and rationality of prediction model have been evaluated. The result indicated that the model had a better fitting accuracy. By comparing the calculated values with a predicted atmospheric corrosion rate of carbon steel after 264h, it showed that its relative error has been just 0.5619% which had higher forecast reliability.

scholarly journals Electrochemistry of active chromium, part III: Effects of temperature

2003 ◽  
Vol 68 (11) ◽  
pp. 871-882 ◽  
Author(s):  
Jovan Popic ◽  
Dragutin Drazic
Keyword(s):  
Corrosion Rate ◽  
Hydrogen Evolution ◽  
Anodic Dissolution ◽  
Electrochemical Corrosion ◽  
Potential Range ◽  
Temperature Dependences ◽  
Hydrogen Evolution Reactions ◽  
Effects Of Temperature ◽  
Best Fit ◽  
Anomalous Dissolution

It was shown that the temperature in the range 20 ? 65 ?C has considerable effects on the electrochemical anodic dissolution of chromium in the active potential range as well as on the electrochemical hydrogen evolution reactions on bare and oxide covered chromium surfaces. Also, the chemical dissolution of chromium is strongly affected. The apparent energy of activation for anodic dissolution is 63.1 kJ mol-1, for hydrogen evolution on a bare Cr surface 19.5 kJ mol-1, for the same reaction on an oxide covered surface 44.0 kJ mol-1 and for the chemical ("anomalous") dissolution 66.9 kJ mol-1. The temperature dependences of the total corrosion rate, and the electrochemical corrosion rate alone, are presented in polynomial forms with the appropriate constants obtained by the best fit of the experimental data. For the hydrogen evolution reaction on both bare and oxide covered chromium, the Volmer-Heyrovsky reaction mechanism with the second step as rate determining was proposed.

scholarly journals Water Permeability of Rust Layer Formed by Atmospheric Corrosion

1970 ◽  
Vol 56 (13) ◽  
pp. 1781-1785 ◽  
Author(s):  
Jiro SATAKE ◽  
Taishi MOROISHI
Keyword(s):  
Water Permeability ◽  
Atmospheric Corrosion ◽  
Rust Layer

scholarly journals ASESMEN KOROSI & ANALISIS RISIKO KUALITATIF PADA VERTIKAL BEJANA TEKAN

2021 ◽  
Vol 8 (2) ◽  
pp. 63-72
Author(s):  
Amam Fachrur Rozie ◽  
D.N Adnyana
Keyword(s):  
Risk Analysis ◽  
Corrosion Rate ◽  
Pressure Vessel ◽  
Atmospheric Corrosion ◽  
Uniform Corrosion ◽  
Vertical Pressure ◽  
Qualitative Risk Analysis ◽  
Non Destructive ◽  
Design Pressure

Keselamatan dan keamanan dalam penggunaan bejana tekan sangat penting dan hal utama dalam penggunaan bejana tekan, terlebih lagi jika bejana tekan tersebut sudah melewati umur desain nya. Penelitian ini bertujuan untuk menilai kelayakan kondisi terkini dari suatu bejana tekan vertikal (vertical pressure vessel) yang telah beroperasi sejak tahun 1970 tetapi berhenti beroperasi pada tahun 2011. Pendekatan penilaian pada bejana tekan vertikal ini berbasis pada metode penilaian korosi dan risiko secara kualitatif. Selain itu juga dipergunakan metode-metode lain dalam aspek penilaian nya seperti visual inspeksi, laju korosi (corrosion rate), Non-Destructive Examination (NDE), software calculation dan analisa risiko kualitatif (qualitative risk analysis). Dari hasil observasi dan inspeksi di dapat tekanan desain (design pressure) adalah 7 kg/cm2, Temperatur desain (design temperature) adalah 61°C dengan material konstruksi adalah SA-283 Gr. C dan standard & code yang dipergunakan adalah ASME Sect. VIII Div. 1 dan API 510 serta beberapa standard & code lainnya. Dari hasil kajian dan kalkulasi di lapangan, maka didapat faktor penyebab kerusakan yang kemungkinan terjadi adalah atmospheric corrosion & uniform corrosion dengan nilai laju korosi adalah sebesar 0,127mm/yr dan tingkat risiko dari bejana tekan vertikal ini masuk dalam kategori 2D yang artinya adalah medium-high dengan maksimal umur pakai sampai usia 27 tahun untuk top head dan 24 tahun dan bottom head serta 23 tahun untuk shell. Sehingga dapat disimpulkan bahwa bejana tekan ini masih aman dan layak dipergunakan dengan batasan-batasan di atas.

Experimental investigation and empirical modeling for corrosion rate prediction of biodegradable zinc based composite considering the effect of constituent materials

2021 ◽  
pp. 095440622110556
Author(s):  
Dayanidhi Krishana Pathak ◽  
Pulak Mohan Pandey
Keyword(s):  
Mechanical Properties ◽  
Corrosion Rate ◽  
Biomedical Applications ◽  
Microwave Sintering ◽  
Research Work ◽  
Simulated Body Fluid Solution ◽  
Corrosion Current ◽  
Essential Elements ◽  
Empirical Modeling ◽  
Corrosion Properties

Biodegradable zinc (Zn) has shown great potential in the area of biomedical applications. Though, the mechanical properties are decisive for the use of Zn for orthopedic and cardiovascular applications. Consequently, one needs to focus on improving the mechanical properties of Zn for its suitability in biomedical applications. Alloying of essential elements of the human body resulted in enhancement of Zn’s mechanical properties in recent years. The corrosion rate of pure Zn is ideal; however, the addition of other elements has resulted in a loss of its ideal corrosion rate. The inclusion of hydroxyapatite (HA) and iron (Fe) in Zn has also been reported in improving the mechanical properties. Hence, a need is raised for the development of a model which can predict the corrosion rate after adding HA along with Fe in Zn. In this research work, empirical based modeling is proposed to predict the corrosion rate, which incorporates the outcome of addition of Fe and HA in Zn. The Zn based materials were fabricated with the help of microwave sintering for developing the empirical model. The corrosion properties of the materials were assessed through a potentiodynamic polarization test in a simulated body fluid solution. The enhanced corrosion rate was attained with the rise in HA (wt%) and Fe (wt%) in Zn. An empirical correlation was established between the influencing controlling parameters (i.e., corrosion current, equivalent weight, and material density) of corrosion rate. Confirmation experiments were conducted to validate the developed model, and the highest error of 6.12% was obtained between the experimental and predicted values exhibiting the efficaciousness of the proposed model.

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