Corrosion Rate Data Research Articles

Carbonation and corrosion of steel in fly ash concrete, concluding investigation of five-year-old laboratory specimens and preliminary field data

Carbonation development and reinforcement corrosion were investigated on concretes exposed for a five-year period at 90% RH, 20 ℃, and 5% CO2, and for a six-year period at natural carbonation. Portland cement-based binders with 0%, 18%, and 30% fly ash were investigated. The fly ash blends showed lower carbonation resistance compared to PC both at laboratory and field exposure, a large difference in carbonation performance was observed between the laboratory exposed specimens. The carbonation rate was fastest on the laboratory specimens and showed square-root time dependency the first 2.5 years, but reduced rate at later age. Deeper carbonation depths were in general observed in the vicinity of the reinforcement compared to the unreinforced laboratory exposed specimens. Not all specimens were fully carbonated at the steel-concrete interface. The correlation between degree of carbonation of the steel-mortar interface, the open circuit potential, and the observed corrosion of the steel bars varied between binders and bar position (top or bottom). The measured corrosion rate in the laboratory exposed (90% RH, 20 ℃, and 5% CO2) carbonated concrete was on average 0.2 μA/cm2, with an upper value of 0.6 μA/cm2. The highest corrosion rate was measured in the fly ash concrete. No corrosion rate data are yet available for the field exposed concretes.

PEMETAAN KOROSIFITAS ATMOSFER MENGGUNAKAN LOGAM BAJA KARBON RENDAH DAN KARBON TINGGI PADA WILAYAH KOTA SURABAYA

Corrosion of metals is inevitable. One of the factors that affect corrosion is environmental conditions that contain pollutants like SO2, NO2, and Cl- which are found in many industrial and seaside areas. Surabaya is an area that has 2 types of conditions. In addition, Surabaya is the capital of the province where infrastructure development is running rapidly. Thus, this study maps the level of atmospheric corrosion in five areas in Surabaya by collecting corrosion rate data for 4 months with weight loss method using AISI 1020 Steel and SK5 Steel as test metals. XRD and SEM-EDX tests were conducted to compare the corrosion results. The average corrosion rate of low carbon steel was 0,6561 mpy and high carbon steel was 1,2523 mpy. The results concluded that the high level of atmospheric corrosivity of low carbon steel is in Sukomanunggal, Bulak, Rungkut, Pakal, Krembangan, and Bubutan sub-districts. The medium level is in Tegalsari, Gubeng, Tenggilis Mejoyo, Karang Pilang, Jambangan, Sawahan, and Dukuh Pakis sub-districts. The low level is in Lakarsantri, Mulyorejo, Simokerto, Sambikerep, Genteng, and Wonokromo sub-districts. Meanwhile, high atmospheric corrosivity levels for high carbon steel are in Krembangan, Karang Pilang, Bulak, Tenggilis Mejoyo, Pakal, and Jambangan sub-districts. The medium level is in Rungkut, Sawahan, Bubutan, Wonokromo, Tegalsari, Sukomanunggal, and Lakarsantri sub-districts. The level is in Dukuh Pakis, Genteng, Gubeng, Simokerto, Sambikerep, and Mulyorejo sub-districts. This mapping is based on the level of corrosion in each sub-district which is influenced by the presence of industry and its geographical location.

Performance Analysis of the Protection Effect Cow Bone and Coconut Shell Particulates on 1170 Aluminium Alloy in Dilute Electrolytes

Particulates of cow bone (CB) and coconut shell (CS) were infused within the microstructure of 1170 aluminium alloy and studied for their influence on the corrosion resistance of the resulting aluminium matrix composites in 3.5% NaCl, 0.05 M H2SO4 and 3.5% NaCl/0.05 M H2SO4 solution by weight loss method. Corrosion rate data shows CB and CS significantly influenced the electrochemical properties of the composite. Protection performance data at 336 h of exposure shows CB and CS particulate significantly reduced the corrosion resistance of the aluminium alloy at all weight compositions in 3.5% NaCl solution. In 0.05% H2SO4 solution, CB improved the corrosion resistance of the composite at 5% - 15% weight composition (37.8%, 23.22% and 23.22%), while CS improved the corrosion resistance at 10% and 20% weight composition (37.65% and 28.52%). The corresponding values for CB in 3.5% NaCl/0.05 M H2SO4 solution occurred at 5% - 15% weight composition (34.26, 31.71% and 22.68%) while for CS it occurred at 10 and 15% weight composition (40.52% and 46.05%). Data from ANOVA statistical tool shows particulate weight composition and exposure time are both relevant determinant variables (greater than the theoretical significance factor) influencing the protection performance outputs of CB and CS with values ranging between 41.82% to 92.5% for weight composition and 5.68% and 53.03% for exposure time. Standard deviation data for CB particulate varied minimally only at 20% weight composition in 3.5% NaCl solution. The corresponding data at other CB weight compositions and for coconut shell at all weight compositions varied significantly due to thermodynamic instability.In 0.05 M H2SO4 and 3.5% NaCl/0.05 M H2SO4 solutions, all standard deviation values for CB and CS particulates (excluding CB at 29% weight composition) at all weight compositions vary minimally from the mean data signifying thermodynamic stability of the electrochemical reactions on the composite surfaces with respect to exposure time. The proportion of data above 20% protection performance for CB and CS particulates in 3.5% NaCl solution is 0% at margins of error of 0%. The corresponding values in 0.05 M H2SO4 solution are 15.18% and 15.32% at margins of error of 40% and 43% while the values from 3.5% NaCl/0.05 M H2SO4 solution are 14.78% and 15.5% at margins of error of 35% and 50%.

Service life prediction and environmental impact evaluation of recycled aggregate concrete with supplementary cementitious materials

The application of recycled aggregate concrete (RAC) can promote the harmonious development of resources and environment. However, the mechanical properties and chloride permeability resistance of RAC are worse than those of natural aggregate concrete (NAC), which limits RAC application in chloride-attack environment. In order to solve this problem, supplementary cementitious material (SCM) is added into RAC to improve its performance. In this research, the changes in durability-based service life of RAC due to the addition of unconventional SCMs composed of red mud (RM), ground granulated blast furnace slag (GGBFS) and/or glass power (GP) have been studied. Based on prepared reinforced concrete specimens with 4 kinds of recycled coarse aggregate (RA) substitution level and 5 kinds of binder composition, the accelerated corrosion tests were conducted for determining corrosion rate. Using the corrosion rate data detected in this paper, combined with the chloride rapid migration coefficient and chloride threshold etc. data, the service lives of reinforced concrete structures with SCMs concrete were found to be much longer than those with Ordinary Portland cement (OPC) concrete. Furthermore, life cycle assessment integrated with strength and service life was performed for concrete with specific mix design to study the effect of unconventional SCMs addition on the environmental behaviors of RAC with different RA content. The results showed that RA substitution level had little effect on material environmental benefits, but the improvement effect of SCMs was obvious. Finally, the multi-criteria analysis method was used to evaluate the overall performance of concrete with different binder composition and RA content in terms of strength, service life and environmental impact. For any substitution level of RA, the SCMs composition with optimal effect in improving overall performance of concrete was 10% RM and 15% GGBFS (percentage by weight of binder).

Performance evaluation of the corrosion protection of admixture of Cymbopogon nardus and Commiphora myrrha on high carbon steel in CH3COOH and C6H8O7 solution

Data from weight loss analysis on the protection performance of the combined admixture of Cymbopogon nardus and Commiphora myrrha (CCM) oil extracts on high carbon steel (HC-S) in 3 M CH3COOH and C6H8O7 acid solution was analysed. CCM extract performed effectively in CH3COOH solution at minimum–maximum values of 53.06% and 80.12% at 168 h of exposure. These value corresponds with corrosion rate data of 1.238 mm/y and 0.525 mm/y relative to corrosion rate of HC-S (2.638 mm/y) at 0% CCM concentration. CCM performed poorly in C6H8O7 solution with minimum–maximum values of 12.83% and 43.81% which corresponds to corrosion rates of 6.115 mm/y and 3.942 mm/y relative to corrosion rate value of 7.015 mm/y at 0% CCM concentration. The protection performance of CCM extract varies more significantly with respect to CCM concentration compared to measurement time. The statistical significance factor of CCM concentration in both acids are 64.85% and 93.93% compared to the corresponding values for measurement time at 25.95% and 4.11%. Standard deviation data for CCM extracts in CH3COOH varied minimally from median values at 0.42% to 1.25% CCM concentration compared to the value at 1.67% CCM concentration. The standard deviation values for CCM in C6H8O7 solution were relatively smaller than the values in CH3COOH solution signifying greater thermodynamic stability. Data shows that 39.3% of CCM protection performance data in CH3COOH is greater than 65% efficiency at margin of error of 18.1%. The corresponding value for CCM in C6H8O7 solution is zero wherewith none of the protection performance data is greater than 65% protection efficiency..

PROTEKSI KOROSI PADA BAJA API 5L DENGAN INHIBITOR ORGANIK EKSTRAK DAUN BAWANG DAYAK (Eleutherme Americana Merr) DALAM LINGKUNGAN HCL 0,5 M

Corrosion is a decrease in metal quality due to an electrochemical reaction with its environment. Many factors can cause corrosion of a material. One of them is due to the influence of the concentration of chloride acid dissolved in water media so that the environment is corrosive (acidic). Corrosion can occur in various forms, ranging from uniform corrosion on the entire metal surface to corrosion that is concentrated in certain parts. There are many methods to inhibit the corrosion process. One of the many methods is the use of inhibitors. Organic inhibitor is a type of inhibitor that is non-toxic, inexpensive, readily available in nature, easy to renew and does not damage the environment. These organic inhibitors are obtained by extracting some materials that exist in nature. In this study, the inhibitor used was Dayak leek. The inhibitor is used on API 5L steel material in 0.5M HCl media. The method used to retrieve the steel corrosion rate data using the weight loss method. The inhibition efficiency reached 99.02% for the addition of an inhibitor with a concentration of 5% with an immersion time of 10 days with a corrosion rate of 4.46 mpy.

Research on corrosion assessment model for buried steel pipelines under dynamic DC stray current based on machine learning

AbstractCoupon tests on the pipeline subjected to metro dynamic DC interference were conducted. The pipe‐to‐soil from 78 sites including off‐potentials (Eoff), on‐potentials (Eon), and corrosion rate data were obtained, and then the dynamic fluctuation parameters of pipe‐to‐soil potentials were analyzed statistically. Further, the Pearson correlation between dynamic statistical parameters of pipe‐to‐soil potentials and corrosion rates was analyzed and showed that the statistical parameter of “roff ⩾ −0.85 V” and “mean[Eoff,cmax]” have a greater correlation with corrosion rate than others. Based on the statistical parameters of Eoff and the machine learning method, the optimal feature subset of the corrosion rate model was selected; meanwhile, it is proved that the negative shift of Eoff plays an important role in the prediction of corrosion rate. Finally, the corrosion rate model for buried steel pipeline under dynamic DC interference was established by random forest (rfr) method on 66 training data, then generalization performance of the model was verified on 12 test data. The results show that mean absolute error and R2 are 0.0358 mm/a and 0.56, respectively, on test data.

General corrosion vulnerability assessment using a Bayesian belief network model incorporating experimental corrosion data for X60 pipe steel

External corrosion is one of the leading causes of pipe failure in the oil and gas industry. In this study, a Bayesian belief network (BBN) model has been developed using corrosion rate (CR) data obtained from experimental test results and analytical burst failure models. The BBN model for CR was coupled with a time marching simulation to obtain corrosion defects and quantify failure pressure capacity. Finally, in a reliability framework, the failure pressure capacity was coupled with operating pressure to obtain the probability of failure. Furthermore, the developed BBN model was used to perform a parametric study to identify the critical parameters for the CR. The outcome of the study indicated that the proposed BBN model can be useful to integrate experimental and analytical models to derive reliability of a pipeline operating under various conditions.

Corrosion Behavior of T2 and B30 Cu-Ni Alloy at Different Seawater Depths of the South China Sea

Through marine natural environment tests, the corrosion behavior of T2 and B30 Cu-Ni alloy at different seawater depths of the South China Sea was studied. The corrosion morphology and corrosion product properties were investigated using different techniques, including 3D optical microscope, scanning electron microscope (SEM), x-ray diffraction analyzer (XRD) and electrochemical impedance spectroscopy (EIS). Based on the environmental factor monitoring data and corrosion rate data, environmental factor influence mechanism on corrosion behavior was discussed The results indicated that the corrosion rate of T2 decreased with seawater depths increasing, while it was opposite for that of B30 Cu-Ni alloy. The evolution law of the corrosion rates of T2 at different seawater depths was mainly controlled by changes in seawater temperature and dissolved oxygen concentration. The effect of hydrostatic pressure was limited on T2 corrosion rate, but high hydrostatic pressure could promote Cl− penetrating into the corrosion product film, forming a uniform corrosion morphology for T2. For B30 Cu-Ni alloy, it was simultaneously affected by dissolved oxygen concentration and hydrostatic pressure, and the corrosion product film was rich in Ni and Fe elements.

In situ mathematically simulation for CO2 internal corrosion in wet natural gas gathering pipelines system by HYSYS

The rate of corrosion due to the presence of carbon dioxide in a carbon steel pipe is an important design consideration for gathering pipelines, particularly in the transport of wet natural gas. To evaluate the corrosion rate in a gathering pipeline, in situ simulation study using HYSYS program employed to predict CO2 corrosion in natural gas gathering pipelines system. The effects of operational conditions, inhibitors, pipe parameters and flow regime on the CO2 corrosion are studied in this paper. Increasing operating pressure leads to increase the pH and decrease the CO2 corrosion rate when the operating pressure over 10 MPa and the solution contents 0.85kmol/m3 iron carbonate. The CO2 corrosion rate does not always increase with temperature, and which will reach a maximum value at 45 °C. A high gas velocity will lead to a high corrosion rate. Less free water present in pipeline may lead to more serious corrosion than that of a large amount of free water. The corrosion rate may be inhibited by liquid hydrocarbon and glycol, and the glycol is not an economic inhibitor, especially when there is a large amount of free water in pipeline. The large diameter and flat pipe are useful for decreasing CO2 corrosion rate. The shear stress and corrosion rate will increase sharply when the slug flow forms in pipeline. Through comparing the data of simulation with field corrosion rate data, feasibility of this numerical simulation method is proved.

Modeling the corrosion rate of carbon steel in carbonated mixtures of MDEA-based solutions using artificial neural network

Amine-based CO2 absorption process has the benefit of purifying produced natural gas and reducing greenhouse gas emissions; however, it is associated with corrosion issues. This work aims to develop a corrosion prediction model for carbon steel in methyldiethanolamine (MDEA)-based binary mixtures with monoethanolamine (MEA), diethanolamine (DEA), or piperazine (PZ) at various concentrations using artificial neural network (ANN). Experimental studies of Q345R steel are performed, and corrosion rate data obtained by weight loss method is used to create a database for training and testing of the ANN model. A backpropagation (BP) multilayer perceptron (MLP) network with three layers is proposed. The number of input variables for the input layer is optimized after performing a correlation analysis. Effect of neuron quantity in the hidden layer on ANN model performance is studied; increasing the neuron quantity in the hidden layer is found to enhance the training accuracy and reduce the testing accuracy. A new index, max absolute relative deviation (MARD), is introduced to quantify the performance of the ANN model. The developed 5-8-1 type ANN model is able to give a MARD of 8.66 %. The same corrosion rate database is used to develop the SVM model, in which radial basis function (RBF) is used as the kernel function, and K-fold cross-validation technique is applied to select the optimal model values. A comparison of performance in both training and testing shows that the ANN model outperforms the SVM model.

Desiccated Microclimates for Heritage Metals: Creation and Management

ABSTRACT Since the early 1970s, archaeologists, conservators, and curators have turned to published guidance for methods of safeguarding archaeological metals in the short and long term. Much of this has appeared in editions of the ubiquitous handbook First Aid for Finds, the most recent of which dates to 1998. A central message across all guidance has been to dry metals post-excavation and prevent their corrosion during storage by desiccating the environment around them. This has been proven crucial for iron, with reports of catastrophic loss of collections arising from inappropriate storage environments. There has long been agreement that an effective, low cost option for desiccation is the packing of artefacts in boxes with a desiccant. Though advice on the details of how to achieve this has evolved over time, what has not changed is the lack of quantified evidence for the methods proposed. Informed by a survey of current practice in the sector, this study investigated quantitatively the many variables involved in creating desiccated microclimates for storage of heritage metals. This paper presents the results of an evaluation of the airtightness of a range of commercially available boxes, the optimum mass of desiccant, the effect of external environments, and preliminary data on the efficiency and risk of drying damp objects with silica gel. A second paper will report the effect of stacking boxes on their airtightness and present data on the accuracy and long-term reliability of humidity indicator cards. The guidance arising from laboratory testing of the hardware and methods for desiccated storage is designed to be achievable and adaptable. Combining these findings with corrosion rate data for iron artefacts allows the escalation of risk to objects from decisions in the storage process to be calculated. Together, these papers offer an evidence-based and practice-focused update to First Aid for Finds.

Passivation process quality in reinforced concrete: effects of polarization periodicity and passivation consolidation parameters on data processing

The passivation process quality was studied considering polarization periodicity, passivation consolidation parameters, and data processing. Passivation process quality in steel reinforcement affects a structure’s planned future service life. Some research has addressed this phenomenon, but its study is complicated by the limits of analog-era data, dispersion in corrosion rate data, and their interpretation. Two series of small reinforced concrete specimens were built using two water/cement ratios and two curing/storage combinations and exposed to the marine environment. Polarization periodicity did not affect passivation/depassivation during passivation but on the data processing. The curing and storage process influenced the tendency towards depassivation. Post-curing storage type affected the cumulative corrosion rate from 1 to 5 μA*day/cm2; this is equivalent to the margin of uncertainty in interpretation.

Dynamic Contact Angle and Corrosion Test Measurements on Cu and CuO-Stearic Acid Modifications on Steel Surfaces

In this study, a copper (Cu) coated steel surface’s dynamic con-tact angle and corrosion rate was compared to the bare steel and stearic acid modified surfaces. Various steps of surface treatment have been performed including electrodeposition of Cu, CuO formation from H2O2 immersion with stearic acid modi-fication to obtain dynamic contact angle and the corrosion rate data. The Cu-coated steel’s dynamic contact angle was increased as it implied the surface after Cu treatment was more hydro-philic than the bare steel, with sliding angle and contact angle hysteresis of 54.9o ± 2.39o and 39.5o ± 1.91o, respectively. How-ever, corrosion test measurements by using a mass loss method to quantify the corrosion rate showed that Cu-coated steel and stearic acid-modified Cu-O coated steel had no remarkable dif-ference in corrosion rate. It was found that the Cu-coated steel and stearic acid-modified Cu-O coated steel had corrosion rate eight times slower than the bare surface.

Inhibition effect of rosemary oil on mild steel corrosion in a water-based petrochemical drilling fluid

Corrosion inhibition of carbon steels applied in water-based petrochemical drilling fluid solution (DFS) with non-toxic chemical compounds is an important focus of research. Rosemary oil (ROS) was evaluated for its corrosion inhibition effect on mild steel (MS) in DFS by the potentiodynamic polarization technique and optical microscopy characterization. The corrosion rate data show that ROS effectively inhibited MS corrosion with an average inhibition efficiency above 90%. ROS displayed anodic type inhibition mechanism. The polarization curves displayed the passivation region, which signified the total surface coverage of MS surface. Morphological images of inhibited MS surface significantly differred from the control MS without ROS, whose surface was severely deteriorated by corrosion pits and grooves.

Ceramics coating materials for corrosion control of crude oil distillation column: Experimental and theoretical studies

Corrosion of stainless steels in atmospheric crude oil distillation column was studied in presence and absence of the ceramic coatings at different temperatures and exposure times using the weight loss technique. Thermal spray coating method was employed to deposit the coating. Weight loss of the stainless steel increased with temperature and time, and significantly decreased in the presence of a coating. Maximum coating efficiency of 93.3% was approached in the presence of Al2O3 coating. Surface morphology investigations using atomic force microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy showed a lower corrosion effect in the presence of a coating. Thickness and porosity of coating were determined to be the most significant factors. Mathematical and statistical analyses were performed as a powerful tool for data representation. Second-order polynomial and exponential models were suggested to represent weight loss data as a function of time and temperature with high correlation coefficients. Corrosion rate data varied with temperature according to the Arrhenius equation. Activation energy without coating is lower, than that with the coating, which indicates that the reaction needs a lower energy in the absence of coating. Petroleum chemistry data and local investigations showed that the main factor influencing the corrosion of crude oil distillation columns is the sulphur content, which had a significant effect more than other contaminates of crude oil.

Corrosion of Crude Oil Distillation Column: Kinetics and Mathematical Views

Corrosion causes of distillation column were studied using mass loss technique and surface morphology investigations as a function of temperature and time. Local and visual examinations were carried out to estimate the damages. Special autoclave apparatus was designed to simulate the real operating conditions and to obtain the corrosion rate data, while scanning electron microscopy and X-ray diffraction were used for surface morphology. Kinetics and mathematical modeling were also applied to correlate the results. It was found that corrosion rate of carbon steel alloy was increased with the increasing temperature and time. Surface morphology supported the mass loss data, and the damage of steel surface was higher at sever operating conditions. Most of corrosion problems were attributed to the presence of sulfur components in crude oil. The reaction is following the zeroth-order rates.

Statistical Investigation as a Tool for Corrosion Data Explanations and Forecasting of Reliable Operating Regions

The research reports the results of the corrosion rate data of mild steel in H3PO4 acid as a function of temperature and inhibitor concentration. Potassium iodide was used as a corrosion inhibitor. The weight loss technique was used to evaluate the corrosion rate data. Mathematical and statistical analyses were used to interpret the results. Descriptive statistical analyses showed the distribution of data deviate from normal distribution, which means that most of corrosion rate data were distributed at higher level of inhibitor concentration and lower level of temperature and this preferable case in pickling process. Three mathematical models were suggested to represent the data with high correlation coefficients.

Corrosion Rate of Low Carbon Steel for Construction Materials in Various NaCl Concentrations

Corrosion rate data of metal materials for construction; particularly carbon steel used in wet environments containing NaCl, is very important due to safety reasons. It is, therefore, necessary to investigate the corrosion rate of construction steel in various NaCl concentrations. The objective of this work is to study the corrosion rate of low carbon steel by varying the concentration of NaCl in distilled water, using a loss of weight method. To carry out this research, 25 low carbon steel samples, of 80x24x3 mm sized coupons, were made. Samples were divided into 7 treatment groups, and weight loss measurements were carried out for 240, 480, 720, 960, 1200, 1440 and 1750 hours, respectively. Experimental data was obtained by totally exposing the samples to NaCl solutions of 2%, 3%, 4% and 5%, and one treatment in distilled water only. The results show that NaCl concentration significantly influenced the corrosion rate for all solution variations. The most obvious effect was observed in the first 240 hours of exposure time for all concentrations of NaCl; which then gradually decreased until an exposure time of 1750 hours was reached. The average corrosion rate value was0.2427 μm/year.

In-situ electrochemical impedance measurements of corroding stainless steel in high subcritical and supercritical water

The traditional method of corrosion studies of structural materials exposed to water at high pressures and temperatures is ex-situ weight gain/loss estimation and analyses of the oxide scales. In this work, in-situ electrochemical impedance spectroscopy (EIS) is applied to study behaviour of 316 L stainless steel exposed to sub-critical and super-critical water (SCW) with the aim to investigate the effect of temperature, in particular close to the critical point of water. As the second objective, the effect of exposure time during the long-term exposure at 500 °C was investigated. Impedance data were analyzed and discussed, based on changes in the physical and chemical properties of water. Instantaneous corrosion rate data, estimated from impedance data, were converted in weight differences and compared with the literature data available for 316 L steel corrosion in SCW. The good agreement obtained supports applicability of in-situ EIS for corrosion studies in super-critical range.