Research of atmospheric corrosion activity on oil pumping stations with tank farms

2021 ◽  
pp. 88-92
Author(s):  
Павел Олегович Ревин ◽  
Алексей Витальевич Макаренко ◽  
Андрей Алексеевич Губенков ◽  
Ирина Олеговна Осина
Keyword(s):  
Corrosion Rate ◽  
Atmospheric Corrosion ◽  
Gravimetric Method ◽  
Steel Corrosion ◽  
Steel Structure ◽  
Climatic Conditions ◽  
International Standards ◽  
Corrosion Activity ◽  
Climatic Regions ◽  
Pumping Stations

В настоящее время в отечественных национальных и международных стандартах отсутствуют данные по коррозионной активности атмосферы регионов, в которых расположены нефтеперекачивающие станции с резервуарными парками, эксплуатируемые российским оператором магистральных нефте- и нефтепродуктопроводов. В нормативных документах ПАО «Транснефть», регламентирующих требования к антикоррозионным покрытиям для наружной поверхности резервуаров, определены три категории коррозионной активности атмосферы по ISO 12944-2:2017. Данная классификация учитывает климатические условия регионов, но не учитывает скорость коррозии стали. В этой связи с целью определения скорости коррозии стальных конструкций в различных климатических районах, где расположены объекты организаций системы «Транснефть», была проведена серия испытаний. На 28 НПС в восьми климатических районах были установлены стенды с образцами из стали 09Г2С. Скорость коррозии металла образцов определяли гравиметрическим методом после выдержки в течение шести месяцев, одного года, двух, трех, четырех и пяти лет. Установлено, что скорость коррозии металлических образцов составила от 55 до 236 г/(м∙год), что соответствует категории коррозионной активности атмосферы С2 и С3 по ISO 12944-2:2017 и ГОСТ 34667.2-2020. Наибольшая скорость коррозии - от 177 до 236 г/(м∙год) - наблюдалась в районах расположения НПС в непосредственной близости от моря (до 1,5 км от береговой линии). Currently, there is no data included in the state and international standards on the corrosion activity of the atmosphere in the regions in which oil pumping stations with tank farms are situated, which are operated by Russian main oil and oil products pipeline operators. In the regulatory documents of Transneft PJSC, which specify the requirement for anticorrosion coatings for the outer surfaces of tanks, three categories of atmospheric corrosion activity are defined as per ISO 12944-2:2017. This classification takes into account the climatic conditions of the regions, but not the steel corrosion rate. In this regard, in order to determine the corrosion rate of steel structure in various climatic regions, where Transneft facilities are situated, a series of tests was performed. The test bench with 09G2S steel samples was installed on 28 oil pumping stations in eight climatic regions. The corrosion rate of the metal samples was determined by the gravimetric method after tempering within the period of six months, one year, two, three, four and five years. It has been established that the corrosion rate of the metal samples amounted from 55 to 236 g/(m·per year), which corresponds to the atmospheric corrosion activity category C2 and C3 as per ISO 12944-2:2017 and GOST 34667.2-2020. The highest corrosion rate, from 177 to 236 g/(m·per year) - was observed in the OPS location regions with close proximity to sea (1,5 km to shore line).

Discussion of Oxygen Threshold Level for Corrosion Management in Seawater Injection Systems

2021 ◽  
Author(s):  
Jean Vicente Ferrari
Keyword(s):  
Corrosion Rate ◽  
Oxygen Reduction ◽  
Water Injection ◽  
Steel Corrosion ◽  
Threshold Level ◽  
International Standards ◽  
Limiting Current ◽  
Order Of Magnitude ◽  
The Impact ◽  
Oxygen Concentrations

Abstract Generally, in water injection systems, oxygen levels starting from around eight ppm are deoxygenated to below 50 ppm, following international standards' guidelines. This work aims to discuss the impact of such a magnitude value of oxygen contamination on steel corrosion in seawater injection systems by analysing theoretical polarisation curves and results from published works with different approaches. Corrosion models consider mass-transfer controlled diffusion of oxygen to predict the maximum steel corrosion rate, which depends on the oxygen limiting current, which in turn is strongly influenced by flow velocity. The effect of free chlorine on corrosion in seawater injection systems has also been considered and included in an oxygen equivalent parameter. In such systems, where oxygen reduction is the key cathodic reaction, the corrosion process may be under cathodic activation control, independent of flow at higher velocities or when erosion-corrosion begins. In this work, theoretical polarisation curves were constructed by using published oxygen and chlorine cathodic limiting currents (iLc) on carbon steel and a noble metal electrode, respectively. Aerated (200 ppb and 9000 ppb of oxygen) and deaerated conditions (50 ppb of oxygen) and the presence of 300 ppb of chlorine were applied to the assumed exchange current densities (io). Neutral (pH 7) and acid (pH 4) conditions (considering the presence of CO2) were also assumed to be at room temperature and pressure. Since the corrosion rate in lower oxygen concentrations (ppb order of magnitude) may result in corrosion rates of the same order of magnitude than in higher oxygen concentrations (ppm order of magnitude) when comparing and analysing results from experimental, semi-empirical or mechanistic approaches, it is necessary to weigh up the effects of both steel surface (bare or scaled/corrosion products) and flow. At oxygen concentrations below 200 ppb and under acid conditions, the contribution of H+ reduction on corrosion rate starts to be higher than oxygen reduction, mainly in the absence of chlorine.

Steel Corrosion Patterns in Neutral and Alkaline Iron Oxide Slurry

2021 ◽  
pp. 142-155
Author(s):  
V.A. Shelontsev ◽  
I.G. Gorichev ◽  
A.V. Kuzin ◽  
I.V. Gerasimova ◽  
E.A. Eliseeva
Keyword(s):  
Iron Oxide ◽  
Corrosion Rate ◽  
Dissolved Oxygen ◽  
Polarization Resistance ◽  
Gravimetric Method ◽  
Sharp Decrease ◽  
Steel Corrosion ◽  
Chloride Ions ◽  
Diffusion Control ◽  
Ph Range

The study identifies and theoretically substantiates the steel corrosion patterns in aqueous slurry of iron-ore concentrate. The purpose of the study was to examine the effect that the content of dissolved oxygen(PO2), pH, the concentration of chloride ions (CCl-) and the rate of movement of the iron oxide slurry (ω) produce on the corrosion losses of steel 20. Comparative analysis of the corrosion rate values obtained by the gravimetric method and the polarization resistance method showed that the reciprocal of the polarization resistance and the corrosion rate change symbatically with increasing pH, the corrosion rate values are quantitatively well consistent with each other. To identify the corrosion patterns, the method of polarization resistance was used. The dependence of the corrosion rate (ρ) on рН revealed two characteristic areas: in the first one, there is no dependence of the rate on pH (6.5--9.0); in the second one, there is a sharp decrease in corrosion losses when the pH goes from 9.0 to 12.5. For pH = 6.5--9.0, the corrosion rate increases linearly with an increase in the partial pressure of oxygen, and corrosion losses in the slurry are higher than in the background solution. The dependence ρ(√ω) is linear over the entire pH range (6.0--9.0), which indicates the diffusion control of the corrosion process. Findings of research show that in order to protect carbon steel from corrosion in the iron oxide slurry, it is necessary to take into account the pH and О2 concentration. Optimal reduction of corrosion losses can be achieved by alkalizing the slurry and removing dissolved oxygen

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.

Evaluation of Atmospheric Corrosivity by ACM Technique

2009 ◽  
Vol 610-613 ◽  
pp. 3-8 ◽  
Author(s):  
Xian Long Cao ◽  
Yi De Xiao ◽  
Hong Da Deng ◽  
Peng Jun Cao ◽  
Bi Jia
Keyword(s):  
Corrosion Rate ◽  
Atmospheric Corrosion ◽  
Early Stage ◽  
Gravimetric Method ◽  
Close Relation ◽  
Test Site ◽  
Electrochemical Process ◽  
Metal Corrosion ◽  
Electrochemical Technique ◽  
Climatic Parameters

The atmospheric corrosion has been shown to be an electrochemical process, the atmospheric corrosion behavior of Q235 stell evaluated with ACM (Atmospheric corrosion monitor) electrochemical technique was investigated in the study. The experimental results showed that there existed a close relation between electrochemical data and climatic parameters was confirmed. Taking into consideration accuracy and sensitivity of electrochemical technique, the ISO-standardized time of wetness (TOW) seems to be too conservative. SO2 seems to be more aggressive than chloride on metal corrosion in the early stage of atmospheric corrosion but the complexion reverses in the final stage of atmospheric corrosion. The ratio of corrosion rate from integration of ACM current to corrosion rate from weight loss of test specimens, that is, cell factor is fairly constant at the same test site but varied greatly between test sites. Based on constant cell factors and close relation between electrochemical data and climatic parameters in all test sites, ACM electrochemical technique can evaluate and classify the short-term atmospheric corrosivity as a substitute for gravimetric method, and the verification shows that atmospheric corrosivity classifications according to integration of ACM current and especially to cell factor coincide with the specifications of ISO Standard.

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.

scholarly journals Investigation of Corrosion Rate and Rust Expansion Form of Segment Reinforcement for Shield Tunnel by Combined Action of Soil Loading, Chloride Ion and Stray Current

2021 ◽  
Vol 13 (6) ◽  
pp. 3444
Author(s):  
Zheng Li ◽  
Hao Jin ◽  
Shuo Yu
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Shield Tunnel ◽  
Uniform Corrosion ◽  
Stray Current ◽  
Soil Loading ◽  
Capacity Degradation ◽  
Expansion Form ◽  
Combined Action

Segment reinforcement corrosion can cause bearing-capacity degradation of shield tunnel, which is unsafe for the metro operation. Therefore, a three-dimensional computational model was proposed in this paper to study the corrosion rate and rust expansion form of segment reinforcement by the combined action of soil loading, chloride ion and stray current. The results show that the arch waist segment steel corrosion rate in the middle is larger than the ends. The rust expansion form of segment reinforcement appears be an eccentric circle. The radius size and circular center are related to the non-uniform corrosion coefficient and the maximum corrosion current density.

Test and Study on Impact of Corrosion on Bond Force between Steel and Concrete

2010 ◽  
Vol 36 ◽  
pp. 176-181
Author(s):  
Xian Feng He ◽  
Shou Gang Zhao ◽  
Yuan Bao Leng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Concrete Structure ◽  
Steel Corrosion ◽  
Reinforced Concrete Structure ◽  
Bond Force ◽  
Steel Bars ◽  
Protection Layer ◽  
Corrosion Of Steel ◽  
The Impact

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.

Steel Corrosion Rate Studies Using Sample Area as a Variable

1988 ◽  
Vol 135 (6) ◽  
pp. 1333-1337 ◽  
Author(s):  
John N. Murray ◽  
Patrick J. Moran
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Sample Area

The Calculation of the Thickness for Uniform Corrosion and Localized Corrosion in Steel Corrosion

2011 ◽  
Vol 255-260 ◽  
pp. 514-518
Author(s):  
Zheng Yi Kong ◽  
Shan Hua Xu ◽  
Yu Sheng Chen
Keyword(s):  
Corrosion Rate ◽  
Constant Temperature ◽  
Safety Assessment ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Power Relationship ◽  
Uniform Corrosion ◽  
Experiment Data ◽  
Temperature And Humidity ◽  
Corrosion Pits

Because of the complexity of corrosion, the law of uniform corrosion and localized corrosion is still not clear,so it is difficult to assess their impact on the structure safety. In order to differ them and find their own law, we obtain a lot of corrosion specimens by ways of constant temperature and humidity, and then detect the size of corrosion pits by roughness tester. After that, the method for calculating the thickness of uniform corrosion and localized corrosion is proposed. Then the method is used to analyze the experiment data. The result indicates the thickness of uniform corrosion and localized corrosion all increase with the rate of corrosion, and they all show a power relationship with corrosion rate, so it will provide a basis for distinguishing them in safety assessment.

Hygrothermal Performance and Degradation of Gypsum Houses in Different Brazilian Climates

2015 ◽  
Vol 3 ◽  
pp. 137-149 ◽  
Author(s):  
R.M.S.F. Almeida ◽  
P. Paula ◽  
A. Santos ◽  
N.M.M. Ramos ◽  
J.M.P.Q. Delgado ◽  
...  
Keyword(s):  
Simulation Software ◽  
International Standards ◽  
Computer Simulation Model ◽  
Water Absorption Coefficient ◽  
Vapour Permeability ◽  
Climatic Regions ◽  
Hygrothermal Simulation ◽  
Durability Assessment ◽  
And Performance

This work consisted of two main lines of research: one of a literature review and other of simulation. In the first part, a modular constructive system based on gypsum blocks is presented. This constructive system reduces the manpower considerably, the time of execution and the final costs of construction. However, the durability assessment should be analysed but first its implementation and performance along the country must analysed.In this work a preliminary experimental characterization of the thermal conductivity, vapour permeability and water absorption coefficient of two different samples of gypsum plasters from the northeast Brazil (plaster pole of Araripe, Pernambuco) was performed. The experimental and analytical procedures followed either international standards or well-established methodologies, supporting the analysis of gypsum walls hygrothermal behaviour. The measured properties were adopted as inputs to hygrothermal simulation software and the analysis of gypsum based exterior walls was conducted for different climate zones and exposure conditions. The study demonstrates the durability issues that may arise in each location, due to differences in hygrothermal action.The other simulation part included hygrothermal advanced modelling, using the EnergyPlus software. The numerical results carried out allow a discussion over the interior comfort and durability of this modular constructive system. In this paper, the computer simulation model and the results of a parametric analysis of the dwelling performance on the eight climatic regions defined in Brazilian regulations are presented. The model was validated using the in situ measurements of air temperature.

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