The electrolyte renewal effect on the corrosion mechanisms of API X65 carbon steel under sweet and sour environments

2021 ◽  
pp. 108347
Author(s):  
B.A.F. Santos ◽  
M.E.D. Serenario ◽  
R.C. Souza ◽  
J.R. Oliveira ◽  
G.L. Vaz ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Renewal Effect ◽  
Corrosion Mechanisms

scholarly journals Formation of Iron Sulfides on Carbon Steel in a Specific Cement Grout Designed for Radioactive Waste Repository and Associated Corrosion Mechanisms

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3563
Author(s):  
Mathieu Robineau ◽  
Valérie Deydier ◽  
Didier Crusset ◽  
Alexandre Bellefleur ◽  
Delphine Neff ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Radioactive Waste ◽  
Corrosion Product ◽  
Product Layer ◽  
Cement Grout ◽  
Radioactive Waste Disposal ◽  
Sulfide Concentration ◽  
Iron Sulfides ◽  
Corrosion Mechanisms ◽  
A Minor

Carbon steel coupons were buried in a specific low-pH cement grout designed for radioactive waste disposal and left 6 months in anoxic conditions at 80 °C. The corrosion product layers were analyzed by µ-Raman spectroscopy, XRD, and SEM. They proved to be mainly composed of iron sulfides, with magnetite as a minor phase, mixed with components of the grout. Average corrosion rates were estimated by weight loss measurements between 3 and 6 µm yr−1. Corrosion profiles revealed local degradations with a depth up to 10 µm. It is assumed that the heterogeneity of the corrosion product layer, mainly composed of conductive compounds (FeS, Fe3S4, and Fe3O4), promotes the persistence of corrosion cells that may lead to locally aggravated degradations of the metal. New cement grouts, characterized by a slightly higher pH and a lower sulfide concentration, should then be designed for the considered application.

The corrosion mechanisms of carbon steel and weathering steel in SO2 polluted atmospheres

1997 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J.H. Wang ◽  
F.I. Wei ◽  
Y.S. Chang ◽  
H.C. Shih
Keyword(s):  
Carbon Steel ◽  
Weathering Steel ◽  
Corrosion Mechanisms

A Review of 25 years of Corrosion Studies on HLW Container Materials at the CEA

2006 ◽  
Vol 985 ◽  
Author(s):  
Max Helie
Keyword(s):  
Carbon Steel ◽  
Base Alloy ◽  
Atomic Energy Commission ◽  
Propagation Rate ◽  
High Level Waste ◽  
Corrosion Resistant ◽  
Nickel Base ◽  
Corrosion Mechanisms ◽  
High Level

ABSTRACTThe Commissariat à l'Énergie Atomique (CEA, French Atomic Energy Commission) has been involved in researches on nuclear waste management for more than 25 years. One of the key issues is the prediction of the long term behavior and aging of the High Level Waste (HLW) containers in order to develop concepts that will ensure the confinement of the activity over extremely long periods of time.Preliminary studies were carried out on two concepts, one of a thin "corrosion resistant" container made of titanium or nickel base alloy, and the other on a thick "corrosion allowance" container made or carbon steel.The results of these experiments showed that the "corrosion resistant" concept led to a high uncertainty on the development and propagation rate of localized forms of corrosion, and the concept of geological disposal in an argillaceous host formation of thick waste containers made of carbon steel was chosen as the reference. Studies are still in progress to better assess the corrosion mechanisms relevant to this situation in order to provide reliable models for the long term prediction of the containers corrosion behavior.

scholarly journals Corrosion of Carbon Steel in Marine Environments: Role of the Corrosion Product Layer

2020 ◽  
Vol 1 (1) ◽  
pp. 198-218
Author(s):  
Philippe Refait ◽  
Anne-Marie Grolleau ◽  
Marc Jeannin ◽  
Celine Rémazeilles ◽  
René Sabot
Keyword(s):  
Carbon Steel ◽  
Corrosion Product ◽  
Metal Surface ◽  
Steel Surface ◽  
Solid Phase ◽  
Product Layer ◽  
Localized Corrosion ◽  
Natural Seawater ◽  
Uniform Corrosion ◽  
Corrosion Mechanisms

This article presents a synthesis of recent studies focused on the corrosion product layers forming on carbon steel in natural seawater and the link between the composition of these layers and the corrosion mechanisms. Additional new experimental results are also presented to enlighten some important points. First, the composition and stratification of the layers produced by uniform corrosion are described. A focus is made on the mechanism of formation of the sulfate green rust because this compound is the first solid phase to precipitate from the dissolved species produced by the corrosion of the steel surface. Secondly, localized corrosion processes are discussed. In any case, they involve galvanic couplings between anodic and cathodic zones of the metal surface and are often associated with heterogeneous corrosion product layers. The variations of the composition of these layers with the anodic/cathodic character of the underlying metal surface, and in particular the changes in magnetite content, are thoroughly described and analyzed to enlighten the self-sustaining ability of the process. Finally, corrosion product layers formed on permanently immersed steel surfaces were exposed to air. Their drying and oxidation induced the formation of akaganeite, a common product of marine atmospheric corrosion that was, however, not detected on the steel surface after the permanent immersion period.

Assessment of Piping Field Failures and Burst Tests on Carbon Steel Pipes With Local Wall Thinning Using ASME Section XI Code Case N-597-2

2009 ◽  
Author(s):  
Kunio Hasegawa ◽  
Toshiyuki Meshii ◽  
Douglas A. Scarth
Keyword(s):  
Carbon Steel ◽  
Accelerated Corrosion ◽  
Steel Pipes ◽  
Pipe Burst ◽  
Evaluation Procedures ◽  
Wall Thinning ◽  
American Society ◽  
Corrosion Mechanisms ◽  
Flow Accelerated Corrosion ◽  
Local Wall Thinning

One of the more common modes of degradation in power plant piping has been wall thinning due to erosion-corrosion or flow-accelerated corrosion. Extensive work has been performed to understand flow-accelerated corrosion mechanisms and develop fracture criteria of locally thinned pipes, since the tragic events at Surry Unit 2 and Mihama Unit 3. A large number of tests have been performed on carbon steel pipes, elbows and tees with local wall thinning. In addition, the American Society of Mechanical Engineers Boiler and Pressure Vessel Code provides procedures in Code Case N-597-2 for evaluation of wall thinning in pipes. This paper provides validation of the evaluation procedures in Code Case N-597-2 by comparing with the field rupture data and pipe burst test data. The allowable wall thinning from the Code Case N-597-2 procedures is shown to maintain adequate margins against rupture.

scholarly journals Anaerobic corrosion of carbon steel in compacted bentonite exposed to natural Opalinus clay porewater: Bentonite alteration study

2021 ◽  
Vol 1 ◽  
pp. 103-104
Author(s):  
Nikoleta Morelová ◽  
Kathy Dardenne ◽  
Nicolas Finck ◽  
Frank Heberling ◽  
Volker Metz ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Steel Corrosion ◽  
Opalinus Clay ◽  
Spectroscopic Techniques ◽  
Clay Rocks ◽  
Corrosion Mechanisms ◽  
High Level ◽  
Mont Terri ◽  
Underground Research Laboratory ◽  
Term Performance

Abstract. Carbon steel is a potential canister material for the disposal of high-level radioactive waste in deep geological repositories in clays and clay rocks. Bentonite is considered as a potential backfill material for those multi-barrier systems. To predict the long-term performance and for safety assessment the knowledge of canister corrosion behavior is important. The corrosion products formed and mineralogically altered bentonite at the canister/bentonite interface can potentially provide an additional barrier against radionuclide migration. In-situ corrosion experiments were performed at the Mont Terri underground research laboratory. Coupons of carbon steel were embedded in Volclay MX-80 bentonite with controlled densities, installed in a borehole under simulated repository and anaerobic conditions and exposed to natural Opalinus clay porewater for a period up to 5.5 years (Smart et al., 2017). In the present study, the bentonite layer at the canister/bentonite interface was characterized by complementary microscopic and spectroscopic techniques (XPS, SEM-EDX, µXANES) under anoxic conditions. The interface revealed reddish-brown staining up to 2 mm depth into the bentonite in the zone adjacent to the steel in all three obtained samples. The XPS analysis revealed formation of sulfides at the interface consisting of iron and other trace metals present in the steel. The SEM-EDX analyses of the interface (embedded cross-cut with steel removed) showed different degrees of calcium enrichment in the bentonite adjacent to the metal for various samples. The µXRF analysis performed on the bentonite at the interface showed a scarce or distinct calcium-enriched rim up to 100 µm into the bentonite and iron-enriched rim depending on the sample (one sample in Fig. 1), while µXANES analysis revealed formation of iron silicate compounds in the reacted reddish-brown zone. The iron appears to displace calcium from the interlayer sites in montmorillonite. The calcium then precipitates at the interface as calcite. The extent of this process seems to be strongly related to the bentonite density. The steel coupon was removed prior to embedding, with the location marked as resin in Fig. 1. A line scan from the edge towards the bulk bentonite did not indicate any systematic gradient in the Fe2+/3+ ratio. The formation of mixed Fe2+/3+ silicate compounds appears to be heterogeneous. This work contributes to an increasing understanding of steel corrosion mechanisms in clay, which can improve the robustness of canister lifetime predictions.

scholarly journals An Investigation of Internal Corrosion of Oil and Gas Transporting Carbon Steel Pipes in the Niger Delta Area of Nigeria

2017 ◽  
Vol 2 (8) ◽  
pp. 22
Author(s):  
Obotowo W. Obot ◽  
Charles N. Anyakwo
Keyword(s):  
Carbon Steel ◽  
Niger Delta ◽  
Oil And Gas ◽  
Co2 Corrosion ◽  
Corrosion Monitoring ◽  
Temperature Oxidation ◽  
Internal Corrosion ◽  
Delta Area ◽  
Steel Pipes ◽  
Corrosion Mechanisms

Internal corrosion of carbon steel pipes of oil and gas Companies in the Niger Delta area of Nigeria using coupons and ER probes is presented. Corrosion mechanisms for the lines vary with the fluid type and operational parameters. Aqueous corrosion with, in some cases CO2 corrosion additive, erosion corrosion and elevated temperature oxidation are corrosion mechanisms implicated in the pipes. No H2S-induced corrosion was observed for all the lines investigated. They act separately or synergistically to exacerbate the corrosion attack.  Application of inhibitors of the amine group drastically lowered the corrosion rates. Effective inhibition regime had in an instance markedly lowered the corrosion rate of a line from 42.7080mpy to 1.3447mpy. The ER probes incorporation offered a comparative corrosion monitoring alternative and provided insight into the real time conditions of the lines over prolonged periods of times. The exercise proved very useful in determining the corrosion status of the pipes and helped to determine the lines that should require immediate maintenance intervention to obviate possible ugly incidents of breakouts and ruptures.

Assessment of Piping Field Failures and Burst Tests on Carbon Steel Pipes With Local Wall Thinning Using ASME Section XI Code Case N-597-2

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Kunio Hasegawa ◽  
Toshiyuki Meshii ◽  
Douglas A. Scarth
Keyword(s):  
Carbon Steel ◽  
Accelerated Corrosion ◽  
Steel Pipes ◽  
Pipe Burst ◽  
Evaluation Procedures ◽  
Wall Thinning ◽  
American Society ◽  
Corrosion Mechanisms ◽  
Flow Accelerated Corrosion ◽  
Local Wall Thinning

One of the more common modes of degradation in power plant piping has been wall thinning due to erosion-corrosion or flow-accelerated corrosion. Extensive work has been performed to understand flow-accelerated corrosion mechanisms and develop fracture criteria of locally thinned pipes since the tragic events at Surry Unit 2 and Mihama Unit 3. A large number of tests have been performed on carbon steel pipes, elbows, and tees with local wall thinning. In addition, the American Society of Mechanical Engineers Boiler and Pressure Vessel Code provides procedures in Code Case N-597-2 for the evaluation of wall thinning in pipes. This paper provides validation of the evaluation procedures in Code Case N-597-2 by comparing with the field rupture data and pipe burst test data. The allowable wall thinning from the Code Case N-597-2 procedures is shown to maintain adequate margins against rupture.

Investigation of Corrosion Mechanisms in a Continuous Catalytic Regeneration (CCR) Platformer Unit

2019 ◽  
Vol 797 ◽  
pp. 393-401 ◽  
Author(s):  
Nur Balqis Rusli ◽  
Najmiddin Yaakob ◽  
Robert Mikhail Savory
Keyword(s):  
Carbon Steel ◽  
Oil And Gas ◽  
Cooling System ◽  
Steel Corrosion ◽  
Oil And Gas Industry ◽  
High Resistivity ◽  
Alloy 800H ◽  
Gas Industry ◽  
Ultimate Failure ◽  
Corrosion Mechanisms

— Corrosion is prevalent throughout the world, none less so than in the oil and gas industry. Managing and mitigating corrosion in refining complexes is of paramount importance in order to prevent undesirable consequences such as major fires, explosions and Boiling Liquid Expanding Vapor Explosion (BLEVE) due to Loss of Primary Containment caused by the thinning and ultimate failure of pipelines and vessel walls. Analysis of a platformer unit at a Malaysian refinery has identified the occurrence of thermal fatigue and erosion corrosion on the Vent Gas Tower (VGT) Caustic Circulation line, which in turn has led to the excessive degradation of the walls of a venturi scrubber and the 8’’ caustic circulation line with initial thickness of 12.70mm. The rate of corrosion (0.88 mm/year) of the 8’’ caustic circulation line exceeds the standard allowable carbon steel corrosion rate (0.1 mm/year) as stated in API 571 Damage Mechanisms Affecting Fixed Equipment in the Refining Industry. This indicates that the circulation line has significant potential to fail which would lead to a major HSE incident. Based on these findings it is recommended that the refinery in question modifies the line by increasing the thickness of the line and include a cooling system to reduce temperature swing (ΔT) to below 93°C. Besides that, it is suggested that the implementation of Corrosion-Resistant Alloys (CRA) is conducted on the line. According to ASME B31.3 and supported by ASTM A 193, the line can be replaced with nickel-based alloy, alloy 800H and killed carbon steel which have high resistivity to corrosion than carbon steel. However, more comprehensive studies need to be conducted to identify the viable mitigation methods that are suitable to be implemented on the Vent Gas Tower (VGT) Caustic Circulation line.

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