Modeling research of initial atmospheric corrosion of Q235 carbon steel based on electrical resistance probe

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhuolin Li ◽  
Dongmei Fu ◽  
Zibo Pei
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Real Time ◽  
Electrical Resistance ◽  
Atmospheric Corrosion ◽  
Steel Corrosion ◽  
Classification Model ◽  
Content Type ◽  
Q235 Carbon Steel ◽  
Corrosion Data

Purpose This paper aims to discover the mathematical model for Q235 carbon steel corrosion date acquired in the initial stage of atmospheric corrosion using electrical resistance probe. Design/methodology/approach In this paper, mathematical approaches are used to construct a classification model for atmospheric environmental elements and material corrosion rates. Findings Results of the experiment show that the corrosion data can be converted into corrosion depth for calculating corrosion rate to obtain corrosion kinetics model and conform corrosion acceleration phase. Combined with corresponding atmospheric environmental elements, a real time grade subdivision model for corrosion rate can be constructed. Originality/value These mathematical models constructed by real time corrosion data can be well used to research the characteristics about initial atmospheric corrosion of Q235 carbon steel.

Long-term prediction on atmospheric corrosion data series of carbon steel in China based on NGBM(1,1) model and genetic algorithm

2019 ◽  
Vol 66 (4) ◽  
pp. 403-411 ◽  
Author(s):  
Yuanjie Zhi ◽  
Dongmei Fu ◽  
Tao Yang ◽  
Dawei Zhang ◽  
Xiaogang Li ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Carbon Steel ◽  
Atmospheric Corrosion ◽  
Data Series ◽  
Data Sets ◽  
Content Type ◽  
Term Prediction ◽  
Long Term Prediction ◽  
Corrosion Data

PurposeThis study aims to achieve long-term prediction on a specific monotonic data series of atmospheric corrosion rate vs time.Design/methodology/approachThis paper presents a new method, used to the collected corrosion data of carbon steel provided by the China Gateway to Corrosion and Protection, that combines non-linear gray Bernoulli model (NGBM(1,1) with genetic algorithm to attain the purpose of this study.FindingsResults of the experiments showed that the present study’s method is more accurate than other algorithms. In particular, the mean absolute percentage error (MAPE) and the root mean square error (RMSE) of the proposed method in data sets are 9.15 per cent and 1.23 µm/a, respectively. Furthermore, this study illustrates that model parameter can be used to evaluate the similarity of curve tendency between two carbon steel data sets.Originality/valueCorrosion data are part of a typical small-sample data set, and these also belong to a gray system because corrosion has a clear outcome and an uncertainly occurrence mechanism. In this work, a new gray forecast model was proposed to achieve the goal of long-term prediction of carbon steel in China.

The electrochemical behavior of corrosion and passivation for Q235 carbon steel in acidic phosphate buffer solutions without and with NO2−

2020 ◽  
Vol 67 (5) ◽  
pp. 473-481
Author(s):  
Xiaochen Hu ◽  
Pei Zhang ◽  
Yong Zhou ◽  
Fuan Yan
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Phosphate Buffer ◽  
Surface Passivation ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Carbon Steels ◽  
Content Type ◽  
Anodic Passivation ◽  
Q235 Carbon Steel

Purpose The purpose of this paper is to reveal the mechanism of nitrite (NO2−) for the surface passivation of carbon steels in acidic environments through investigating the influences of 0.01 mol/L NaNO2 addition on the corrosion and passivation behaviors of Q235 carbon steel in acidic phosphate buffer (APB) solutions (pH 2 to 6). Design/methodology/approach The electrochemical techniques including open circle potential evolution, potentiodynamic polarization, electrochemical impedance spectroscopy and cyclic voltammetry were applied. Findings In APB solutions without NO2−, the Q235 steel presented the electrochemical behaviors of activation (A), activation-passivation-transpassivation and self-passivation-transpassivation at pH 2 to 4, pH 5 and pH 6, respectively; the corrosion rate decreased with the up of pH value, and the surface passivation occurred in the pH 5 and pH 6 solutions only: the anodic passivation at pH 5 and the spontaneous passivation at pH 6. Originality/value In APB solutions without NO2−, the corrosion rate decreased with the up of pH value, and the surface passivation occurred in the pH 5 and pH 6 solutions only: the anodic passivation at pH 5 and the spontaneous passivation at pH 6. With the addition of 0.01 mol/L NaNO2, into APB solutions, the variation of corrosion rate showed the same rule, but the surface passivation occurred over the whole acidic pH range, including the anodic passivation at pH 2 to 4 and the spontaneous passivation at pH 5 to 6.

Effect of relative humidity on corrosion of Q235 carbon steel under thin electrolyte layer in simulated marine atmosphere

2020 ◽  
Vol 67 (2) ◽  
pp. 187-196 ◽  
Author(s):  
Qingqing Song ◽  
Xudong Wang ◽  
Boyang Pan ◽  
Lei Wan
Keyword(s):  
Carbon Steel ◽  
Environmental Factors ◽  
Corrosion Rate ◽  
Relative Content ◽  
Electrolyte Layer ◽  
Corrosion Morphology ◽  
Content Type ◽  
Electrochemical Device ◽  
Thin Electrolyte Layer ◽  
Q235 Carbon Steel

Purpose The purpose of this paper is to obtain the environmental factor, which has the greatest effect on the corrosion rate of Q235 carbon steel under thin electrolyte layer, and to analyze the effect of this factor on the corrosion morphology, corrosion products and polarization process of Q235 carbon steel. Design/methodology/approach An electrochemical device, which can be used under thin electrolyte layer is designed to measure the corrosion current in different environments. Response surface methodology (RSM) is introduced to analyze the effect of environmental factors on corrosion rate. Scanning electron microscope (SEM) and X-ray diffraction (XRD) technique are used to analyze the results. The Tafel slopes of anode and cathode in different humidity and solution are calculated by least square method. Findings The three environmental factors are ranked according to importance, namely, humidity, temperature and chloride ion deposition rate. In a high humidity environment, the relative content of α-FeOOH in the corrosion product is high and the relative content of β-FeOOH is low. The higher the humidity, the lower the degree of anodic blockage, whereas the degree of cathodic blockage is independent of humidity. The above experiments confirm the effectiveness and efficiency of the device, indicating it can be used for the screening of corrosive environmental factors. Originality/value In this paper, an electrochemical device under thin film is designed, which can simulate atmospheric corrosion well. Subsequent SEM and XRD confirmed the reliability of the data measured by this device. The introduction of a scientific RSM can overcome the limitations of orthogonal experiments and more specifically and intuitively analyze the effects of environmental factors on corrosion rates.

Use of the grey relational analysis method to determine the important environmental factors that affect the atmospheric corrosion of Q235 carbon steel

2015 ◽  
Vol 62 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Xianlong Cao ◽  
Hongda Deng ◽  
Wei Lan
Keyword(s):  
Carbon Steel ◽  
Environmental Factors ◽  
Grey Relational Analysis ◽  
Atmospheric Corrosion ◽  
Analysis Method ◽  
Grey System ◽  
Content Type ◽  
Relational Analysis ◽  
Q235 Carbon Steel ◽  
Grey Relational

Purpose – The purpose of this study was to evaluate the grey relational analysis method as a way of determining quickly the important factors affecting the atmospheric corrosion of Q235 carbon steel in one year. Design/methodology/approach – Atmospheric corrosion exposure tests on Q235 steel were carried out at seven typical test sites in China. The test period lasted one year. The corrosion rate of the Q235 test panels was determined using the weight-loss method and environmental factors were monitored and recorded by standard methods. The importance of the various environmental factors was evaluated using the grey relational analysis method. Findings – The results obtained by the grey relational analysis method showed that the ranking order of factors affecting the corrosion of Q235 carbon steel from “slightly” to “severely” was as follows: relative humidity > dew days > SO3 > pH value of rain > rain precipitation > temperature > rainy days > Cl− > H2S > NO2. Furthermore, the initial atmospheric corrosion of Q235 carbon steel was recognized as being the corrosion of the smooth surface by water medium, or acidic aqueous solution. Originality/value – Materials corrosion can be defined as a grey system because corrosion has a clear outcome and complex but uncertain characteristics. The grey relational analysis method, a part of grey system theory, is an effective and quick data processing method that can be used to sort out the degree of correlation of environmental factors affecting atmospheric corrosion in terms of it being a grey system with a lot uncertain information.

Toward a mechanistic understanding of the magnetic field effect on N-80 carbon steel corrosion in aqueous HCl solution

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abbas Hashemizadeh ◽  
Mohammad Javad Ameri
Keyword(s):  
Magnetic Field ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Magnetic Field Effect ◽  
Steel Corrosion ◽  
Reaction Cell ◽  
Content Type ◽  
Elapsed Time ◽  
First Time ◽  
The Magnetic Field

Purpose This study aims to describe the effect of magnetic field (MF) on the corrosion rate of N-80 carbon steel [N-80 carbon steel (CS)] in concentrated (12.5 Wt.%, 3.8 M) hydrochloric acid (HCl) using gravimetric weight loss (WL) measurements and potentiodynamic polarization (PDP) in various conditions at ambient temperature. Design/methodology/approach The effects of MF intensity, magnetization time and elapsed time on corrosion rate (CR) reduction (η) were studied. Findings The experimental results show that pre-magnetization of HCl sharply decreases the corrosion rate of N-80 carbon steel (CS) in acid. The maximum η was found to be 94%. The surface of CS was analyzed with scanning electron microscope in normal and magnetized acid. Originality/value To the best of the authors’ knowledge, no studies have delved into the effects of magnetization on the corrosion rate of CS in concentrated HCl solutions. All of the previous research studies deal with an external MF that is applied on the reaction cell, but the magnetization of fluid before coming in contact with CS is investigated for the first time. In the present work, the influence of MF on the corrosion rate of CS in HCl is illustrated using gravimetric WL and PDP methods. The effects of MF intensity as well as period of magnetization and elapsed time were verified in more than 35 tests.

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 The effect of volatile organic acids and CO2 on the corrosion rate of carbon steel from a Top-of-Line-Corrosion (TLC) perspective

2021 ◽  
Vol 1201 (1) ◽  
pp. 012079
Author(s):  
S B Gjertsen ◽  
A Palencsar ◽  
M Seiersten ◽  
T H Hemmingsen
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Organic Acid ◽  
Carbonic Acid ◽  
Acid Corrosion ◽  
Iron Concentration ◽  
Critical Factor ◽  
Steel Corrosion ◽  
Carbon Steels ◽  
Corrosion Rates

Abstract Models for predicting top-of-line corrosion (TLC) rates on carbon steels are important tools for cost-effectively designing and operating natural gas transportation pipelines. The work presented in this paper is aimed to investigate how the corrosion rates on carbon steel is affected by acids typically present in the transported pipeline fluids. This investigation may contribute to the development of improved models. In a series of experiments, the corrosion rate differences for pure CO2 (carbonic acid) corrosion and pure organic acid corrosion (acetic acid and formic acid) on X65 carbon steel were investigated at starting pH values; 4.5, 5.3, or 6.3. The experiments were conducted in deaerated low-salinity aqueous solutions at atmospheric pressure and temperature of 65 °C. The corrosion rates were evaluated from linear polarization resistance data as well as mass loss and released iron concentration. A correlation between lower pH values and increased corrosion rates was found for the organic acid experiments. However, the pH was not the most critical factor for the rates of carbon steel corrosion in these experiments. The experimental results showed that the type of acid species involved and the concentration of the undissociated acid in the solution influenced the corrosion rates considerably.

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