Assessment of API pipeline steel surface and its environmental vulnerability

2020 ◽  
Author(s):  
O. S. I. Fayomi ◽  
M. Mashilo ◽  
A. P. I. Popoola ◽  
O. Agboola
Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Lijuan Chen ◽  
Bo Wei ◽  
Xianghong Xu

The influence of sulfate-reducing bacteria (SRB) on the corrosion behaviors of X80 pipeline steel was investigated in a soil environment by electrochemical techniques and surface analysis. It was found that SRB grew well in the acidic soil environment and further attached to the coupon surface, resulting in microbiologically influenced corrosion (MIC) of the steel. The corrosion process of X80 steel was significantly affected by the SRB biofilm on the steel surface. Steel corrosion was inhibited by the highly bioactive SRB biofilm at the early stage of the experiment, while SRB can accelerate the corrosion of steel at the later stage of the experiment. The steel surface suffered severe pitting corrosion in the SRB-containing soil solution.


2018 ◽  
Vol 65 (1) ◽  
pp. 97-106 ◽  
Author(s):  
L.M. Quej-Ake ◽  
A. Contreras

Purpose The purpose of this work is to study the corrosion rate of X52 pipeline steel exposed to three types of soils collected in Campeche State in México. The electrochemical evaluation for X52 steel exposed to soils ranging from saturated soil until dry conditions was carried out for a period of 21 days. Owing to its versatility to study the steel corrosion process exposed to different types of soils, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and cyclic voltammetry tests were performed. Additionally, optical and electronic microscopy observations of the steel surface were carried out. Design/methodology/approach Electrochemical cell arrangement was described elsewhere (Quej-Ake et al., 2014). Owing to soil being an electrolytic system with high resistivity and impedance, all electrodes were placed as close as possible, and iR-drop compensation was taken into account using two rods of graphite as an auxiliary electrode. In addition, the conductivity of the soil (Rs) obtained from EIS was used to correct the potential of the working electrode according to iR-drop, and an analysis of ohmic drop from the polarization curves was carried out. Findings Saturated conditions of the three soils were initially considered as the most corrosive conditions for X52 steel surface. Finally, 21 days of immersion time was taken into account as the more drastic condition. So, according to results, X52 steel exposed to beach sand was more susceptible to the corrosion process (0.092 mm/year). iR corrected was negligible at low over-potentials region in saturated soils, which is inside the linear region of Tafel or the activation region. In addition, high cathodic peak potential value obtained from cyclic voltammetry for X52 steel exposed to saturated soil may be attributed to hydrogen evolution reaction and neutral pH. Research limitations/implications The paper has implications for research. It bridges the gap between theory and practice. Originality/value Cyclic voltammetry is a really important tool for the electrochemical analysis of the pipeline steel surface exposed to saturated soils, but is not adequate for analysis of steel exposed to dried soils. In addition, the physicochemical results show that fissures, voids and extra-oxygen presence could also affect the electrochemical responses obtained for X52 steel exposed to soils.


2015 ◽  
Vol 39 (6) ◽  
pp. 4860-4868 ◽  
Author(s):  
Li Hao ◽  
Yu Sirong ◽  
Han Xiangxiang

ZnO coating with upright micro–nano structures was fabricated via electrodeposition and hydrothermal treatment. After it was modified by fluorination, the ZnO coating presented superhydrophobicity with the water CA of 157.59° and the SA was less than 10°.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4206
Author(s):  
E. Sanchez-Salazar ◽  
E. Vazquez-Velez ◽  
J. Uruchurtu ◽  
J. Porcayo-Calderon ◽  
M. Casales ◽  
...  

A gemini surfactant imidazoline type, namely N-(3-(2-fatty-4,5-dihydro-1H-imidazol-1-yl) propyl) fatty amide, has been obtained from the fatty acids contained in the mango seed and used as a CO2 corrosion inhibitor for API X-120 pipeline steel. Employed techniques involved potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. These tests were supported by detailed scanning electronic microscopy (SEM) and Raman spectroscopy studies. It was found that obtained gemini surfactant greatly decreases the steel corrosion rate by retarding both anodic and cathodic electrochemical reactions, with an efficiency that increases with an increase in its concentration. Gemini surfactant inhibits the corrosion of steel by the adsorption mechanism, and it is adsorbed on to the steel surface according to a Langmuir model in a chemical type of adsorption. SEM and Raman results shown the presence of the inhibitor on the steel surface.


2019 ◽  
Author(s):  
Chem Int

Aqueous extract of Thevetia peruviana leaves were investigated as corrosion inhibitor for API 5L X80 pipeline steel in 1M H2SO4 solution using electrochemical and gravimetric techniques. The results reveal that T. peruviana inhibited the X80 pipeline steel corrosion in the acid medium in a concentration dependent manner. Potentiodynamic polarization results showed T. peruviana to be a mixed type inhibitor in 1M H2SO4 environment, whereas the impedance results revealed adsorption of the inhibitor species on the steel surface. The gravimetric results reveal that the adsorption mechanism of the inhibitor on the steel surface was chemisorption. The adsorption was in accordance with Freundlich adsorption isotherm and negative standard adsorption energy (Δ𝐺o𝑎𝑑𝑠) obtained inferred that the adsorption was spontaneous and the interaction between the inhibitive molecules was found to be repulsive. Scanning electron microscopy (SEM) confirmed the formation of adsorbed film on the X80 pipeline steel surface. Results revealed that T. peruviana has potential to inhibit the correction and could possibly be used for corrosion inhibition in the acidic environment of steel.


Author(s):  
N. C. Ngobiri ◽  
K. N. Kikanme

The capacity of aqueous Tetracarpidium conophorum Shell (TCE) Extract to inhibit pipeline steel corrosion in 0.25 M H2SO4 acid was investigated using weight loss and Uv-visible spectroscopy techniques. The phytochemical components of Tetracarpidium conophorum were identified using GC-MS analysis. The results obtained shows that aqueous Tetracarpidium conophorum shell extract decreased the corrosion rate, while the corrosion inhibition efficiency increased with increase in exatract concentration. The Uv-visible spectra indicated a chemical interaction between the TCE molecules and atoms of Iron on the pipeline steel surface, while GC-MS analysis showed the presence of organic compounds with hetero-atoms for adsorption on the steel surface.


CORROSION ◽  
10.5006/3278 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1487-1501 ◽  
Author(s):  
Limin He ◽  
Yunze Xu ◽  
Xiaona Wang ◽  
Yi Huang

The corrosion progression of X65 pipeline steel, which was partly covered by a mineral deposit layer, was investigated in oxygen-containing artificial seawater using a multielectrode array (MEA) and electrical resistance method. Results show that the deposit covered area would act as the anodes due to the oxygen concentration difference between the bare steel area and deposit covered area. The most serious corrosion would occur at the bare steel area which was close to the sand deposit due to the diffusion of the cations from the deposit covered area to the bare steel area, leading to the decrease of local pH. Once the diffusion path between the bare steel area and the deposit covered area was blocked, the bare steel area would act as a constant cathode, resulting in the formation of a protective calcium carbonate layer on the bare steel surface.


Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.


2020 ◽  
Vol 82 (5) ◽  
pp. 11-20
Author(s):  
D.R. Abdulina ◽  
◽  
L.M. Purish ◽  
G.O. Iutynska ◽  
◽  
...  

The studies of the carbohydrate composition of the sulfate-reducing bacteria (SRB) biofilms formed on the steel surface, which are a factor of microbial corrosion, are significant. Since exopolymers synthesized by bacteria could activate corrosive processes. The aim of the study was to investigate the specificity of commercial lectins, labeled with colloidal gold to carbohydrates in the biofilm exopolymeric matrix produced by the corrosive-relevant SRB strains from man-caused ecotopes. Methods. Microbiological methods (obtaining of the SRB biofilms during cultivation in liquid Postgate B media under microaerophilic conditions), biochemical methods (lectin-binding analysis of 10 commercial lectins, labeled with colloidal gold), transmission electron microscopy using JEM-1400 JEOL. Results. It was shown using transmission electron microscopy that the binding of lectins with carbohydrates in the biofilm of the studied SRB strains occurred directly in the exopolymerіс matrix, as well as on the surfaces of bacterial cells, as seen by the presence of colloidal gold particles. For detection of the neutral carbohydrates (D-glucose and D-mannose) in the biofilm of almost all studied bacterial strains PSA lectin was the most specific. This lectin binding in biofilms of Desulfotomaculum sp. К1/3 and Desulfovibrio sp. 10 strains was higher in 90.8% and 94.4%, respectively, then for ConA lectin. The presence of fucose in the SRB biofilms was detected using LABA lectin, that showed specificity to the biofilm EPS of all the studied strains. LBA lectin was the most specific to N-аcetyl-D-galactosamine for determination of amino sugars in the biofilm. The amount of this lectin binding in D. vulgaris DSM644 biofilm was 30.3, 10.1 and 9.3 times higher than SBA, SNA and PNA lectins, respectively. STA, LVA and WGA lectins were used to detect the N-acetyl-Dglucosamine and sialic acid in the biofilm. WGA lectin showed specificity to N-acetyl-D-glucosamine in the biofilm of all the studied SRB; maximum number of bounded colloidal gold particles (175 particles/μm2) was found in the Desulfotomaculum sp. TC3 biofilm. STA lectin was interacted most actively with N-acetyl-D-glucosamine in Desulfotomaculum sp. TC3 and Desulfomicrobium sp. TC4 biofilms. The number of bounded colloidal gold particles was in 9.2 and 7.4 times higher, respectively, than using LVA lectin. The lowest binding of colloidal gold particles was observed for LVA lectin. Conclusions. It was identified the individual specificity of the 10 commercial lectins to the carbohydrates of biofilm matrix on the steel surface, produced by SRB. It was estimated that lectins with identical carbohydrates specificity had variation in binding to the biofilm carbohydrates of different SRB strains. Establishing of the lectin range selected for each culture lead to the reduction of the scope of studies and labor time in the researching of the peculiarities of exopolymeric matrix composition of biofilms formed by corrosiverelevant SRB.


Sign in / Sign up

Export Citation Format

Share Document