Understanding the Propagation of Nonuniform Corrosion on a Steel Surface Covered by Marine Sand

CORROSION ◽  
10.5006/3278 ◽  
2019 ◽  
Vol 75 (12) ◽  
pp. 1487-1501 ◽  
Author(s):  
Limin He ◽  
Yunze Xu ◽  
Xiaona Wang ◽  
Yi Huang
Keyword(s):  
Steel Surface ◽  
Pipeline Steel ◽  
Diffusion Path ◽  
Mineral Deposit ◽  
Concentration Difference ◽  
Marine Sand ◽  
Covered Area ◽  
Bare Steel ◽  
Sand Deposit ◽  
Deposit Layer

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.

scholarly journals Effect of Sulfate-Reducing Bacteria (SRB) on the Corrosion of Buried Pipe Steel in Acidic Soil Solution

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Lijuan Chen ◽  
Bo Wei ◽  
Xianghong Xu
Keyword(s):  
Soil Solution ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Electrochemical Techniques ◽  
Sulfate Reducing Bacteria ◽  
Acidic Soil ◽  
Microbiologically Influenced Corrosion ◽  
Soil Environment ◽  
Sulfate Reducing ◽  
Reducing Bacteria

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.

Effect of cold rolling on hydrogen diffusion and trapping in X70 pipeline steel

2020 ◽  
pp. 1-28
Author(s):  
Alen Thomas ◽  
Jerzy Szpunar
Keyword(s):  
Cold Rolling ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Pipeline Steel ◽  
Effective Diffusion ◽  
Diffusion Path ◽  
X70 Pipeline Steel ◽  
Diffusion Parameters ◽  
Intensity Changes ◽  
Diffusion Intensity

Abstract In this investigation, we prepared samples with five different grain misorientations by cold rolling an X70 pipeline steel plate. The hydrogen permeation and hydrogen visualization experiments were used to compute the diffusion parameters and to reveal the diffusion path in steel samples. The dual-polarized permeation experiment allowed us to show that permeability and effective diffusion coefficient were decreased with an increase in misorientation. Hence, the total and irreversible trapping sites were also raised with the extent of deformation in the steel. On the other hand, the visualization study permitted us to show that hydrogen diffusion intensity changes within the microstructure. The diffusion intensity increases in the order of non-deformed grains, grain boundaries and deformed grains with deformed grains as the easiest path for hydrogen diffusion.

Electrochemical study on the corrosion rate of X52 steel exposed to different soils

2018 ◽  
Vol 65 (1) ◽  
pp. 97-106 ◽  
Author(s):  
L.M. Quej-Ake ◽  
A. Contreras
Keyword(s):  
Cyclic Voltammetry ◽  
Corrosion Rate ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Corrosion Process ◽  
Saturated Soil ◽  
Saturated Soils ◽  
Content Type ◽  
Ir Drop ◽  
X52 Steel

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.

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
Keyword(s):  
Steel Surface ◽  
Pipeline Steel ◽  
Environmental Vulnerability

Preparation of a biomimetic superhydrophobic ZnO coating on an X90 pipeline steel surface

2015 ◽  
Vol 39 (6) ◽  
pp. 4860-4868 ◽  
Author(s):  
Li Hao ◽  
Yu Sirong ◽  
Han Xiangxiang
Keyword(s):  
Hydrothermal Treatment ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Nano Structures

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°.

Cathodic Protection Analysis of Spools With GRP Cover

2017 ◽  
Author(s):  
Randi B. Kongstein ◽  
Rannveig Kvande
Keyword(s):  
Cathodic Protection ◽  
Steel Surface ◽  
Ionic Current ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Large Current ◽  
Bare Steel ◽  
Glass Fibre Reinforced ◽  
Current Lines ◽  
Subsea Pipelines

Cathodic protection (CP) design of pipelines is generally described in internationally recognized standards and recommended practices. However, not all cases can be solved by conventional CP calculations as recommended approaches and methods may not be fully defined in the standards. For instance, Glass fibre Reinforced Polyester (GRP) covers can be applied for mechanical protection (e.g. from trawl and/or dropped object) of subsea pipelines and structures. These GRP covers will restrict the electrical/ionic current lines between the anode and the steel surface to be cathodically protected. For a spool with in-line components requiring a large current (e.g. painted or bare steel) and with a GRP cover it may be difficult to obtain sufficient cathodic protection when applying simple mathematical calculations. This paper describes how the Finite Element Method (FEM) in COMSOL Multiphysics can be applied to show that the potential is acceptable for such cases.

scholarly journals Use of a Gemini-Surfactant Synthesized from the Mango Seed Oil as a CO2-Corrosion Inhibitor for X-120 Steel

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4206
Author(s):  
E. Sanchez-Salazar ◽  
E. Vazquez-Velez ◽  
J. Uruchurtu ◽  
J. Porcayo-Calderon ◽  
M. Casales ◽  
...  
Keyword(s):  
Corrosion Inhibitor ◽  
Steel Surface ◽  
Gemini Surfactant ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Steel Corrosion ◽  
Co2 Corrosion ◽  
Mango Seed ◽  
Spectroscopy Studies ◽  
Corrosion Of Steel

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.

scholarly journals Reinterpretation of the Neogene sediments of the Bree Uplift, NE Belgium

2020 ◽  
Vol 23 (3-4) ◽  
Author(s):  
Rik HOUTHUYS ◽  
Johan MATTHIJS
Keyword(s):  
Tidal Basin ◽  
Marine Sand ◽  
Tectonically Active ◽  
Roer Valley Graben ◽  
Stratigraphic Position ◽  
Neogene Sediments ◽  
Geological Map ◽  
Sand Deposit ◽  
Seismic Sections ◽  
Drill Holes

The present geological map of the Flemish Region shows a small lens-shaped isolated outcrop of the Miocene Bolderberg, Diest and Kasterlee Formations, surrounded by younger formations, in an area that coincides with the tectonic Bree Uplift segment, on the southwestern border of the Roer Valley Graben in NE Limburg. The fault, bordering the segment at its SW side, had been interpreted to be tectonically active throughout the Neogene. Now, it is argued that an erroneous lithostratigraphic interpretation of the outcropping strata supported that view. Field observations of some of the outcrops and sampled drill holes show that the sediments do not belong to an Opitter member of the Bolderberg Formation, a Gruitrode Mill member of the Diest Formation and a Dorperberg member of the Kasterlee Formation, but most probably to the lower, latest Miocene or early Pliocene part of the Mol Formation and an unknown Pliocene marginal marine deposit not unlike and at about the stratigraphic position of the Poederlee Formation. That glauconiferous sand deposit, which has always been interpreted as consisting of two successive sedimentary cycles, is now accommodated in a single cycle, using the sedimentary model of deposition in a confined, backbarrier tidal basin subject to marine sand input and local stages of flow constriction and intraformational incision. Like already proposed by Rossa (1986) and Demyttenaere (1989), reprocessed seismic sections show only minor movements along the southwestern fault of the Bree Uplift since the Paleocene, and no inverse tectonic movements at all since the Middle Miocene.

Corrosion inhibition of API 5L X80 pipeline steel in acidic environment using aqueous extract of Thevetia peruviana

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Corrosion Inhibition ◽  
Aqueous Extract ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Steel Corrosion ◽  
Dependent Manner ◽  
Acidic Environment ◽  
X80 Pipeline Steel ◽  
Concentration Dependent Manner ◽  
Thevetia Peruviana

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.

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