Corrosion Behavior of Carbon Steel in Bicarbonate (HCO3) Solutions

2002 ◽  
Vol 713 ◽  
Author(s):  
Junhua Dong ◽  
Toshiyasu Nishimura ◽  
Toshiaki Kodama
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Ph Value ◽  
Film Formation ◽  
Radioactive Waste Disposal ◽  
Chemical Compositions ◽  
High Concentrations ◽  
Bicarbonate Solutions ◽  
The Stability ◽  
High Level

ABSTRACTCarbon steel is considered in Japan the most promising candidate material for overpacks in high-level radioactive waste disposal. Effects of bicarbonate solutions on the corrosion behavior and corrosion products of carbon steel were investigated by electrochemical measurements; FT-IR spectra and XRD pattern analyses. The results of the anodic polarization measurements showed that bicarbonate (HCO3) accelerates the anodic dissolution and the outer layer film formation of carbon steel in the case of high concentrations, whereas it inhibits these processes in the case of low concentrations. The FTIR and XRD analyses of the anodized film showed that siderite (FeCO3) was formed in 0.5 to 1.0mol/L bicarbonate solution, and Fe2(OH)2CO3 in 0.1 to 0.2mol/L bicarbonate solution, while Fe6(OH)12CO3 was formed in 0.02 to 0.05mol/L bicarbonate solution. In all cases the pH value was around 8.3. The stability of these chemical compositions was discussed using a potential – pH diagram for the Fe-H2O-CO2 system.

Corrosion Behavior of Carbon Steel for the Overpack in the Groundwater Containing Bicarbonate Ions

2008 ◽  
Author(s):  
Toshiyasu Nishimura ◽  
Junpha Dong
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Film Formation ◽  
Corrosion Products ◽  
Radioactive Waste Disposal ◽  
Bicarbonate Ions ◽  
Ft Ir ◽  
High Concentrations ◽  
Bicarbonate Solutions ◽  
High Level

Carbon steel is considered in Japan the candidate material for overpacks in high-level radioactive waste disposal. Effects of bicarbonate solutions on the corrosion behavior and corrosion products of carbon steel were investigated by electrochemical measurements, FT-IR and XRD analyses. The anodic polarization measurements showed that bicarbonate ions (HCO3−) accelerated the anodic dissolution and the outer layer film formation of carbon steel in the case of high concentrations, on the other hand, it inhibited these processes in the case of low concentrations. The FT-IR and XRD analyses of the anodized film showed that siderite (FeCO3) was formed in 0.5 to 1.0mol/L bicarbonate solution, and Fe2(OH)2CO3 in 0.1 to 0.2mol/L bicarbonate solution, while Fe6(OH)12CO3 was formed in 0.02 to 0.05mol/L bicarbonate solutions. The stability of these corrosion products was able to be explained by using the actual potential – pH diagrams for the Fe-H2O-CO2 system.

Experimental Investigation of Passivation Behavior and Corrosion Rate of Carbon Steel in Compacted Bentonite

1997 ◽  
Vol 506 ◽  
Author(s):  
N. Taniguchi ◽  
A. Honda ◽  
H. Ishikawa
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Anodic Polarization ◽  
Radioactive Waste Disposal ◽  
General Corrosion ◽  
External Current ◽  
Compacted Bentonite ◽  
Aqueous Conditions ◽  
High Level

ABSTRACTCarbon steel is one of the candidate materials for overpacks for high-level radioactive waste disposal in Japan. Passivation behavior and corrosion rate of carbon steel were investigated by electrochemical measurements under simulated repository conditions. The results of the anodic polarization measurements showed that carbon steel was hard to passivate in highly compacted bentonite. Therefore, general corrosion seems to be most probable in repository conditions. In order to monitor the in-situ general corrosion rate in compacted bentonite, the AC impedance of carbon steel was measured under aerated conditions. It was confirmed that the corrosion rate in saturated bentonite decreased with time and it was almost the same as that observed in deaerated aqueous conditions. The corrosion rate did not increase in the presence of corrosion products formed by external current supply.

Geodynamic aspects of high-level radioactive waste disposal: a case-study of Nizhnekansky massif

2021 ◽  
pp. 108-112
Author(s):  
V. N. Tatarinov ◽  
V. N. Morozov ◽  
A. I. Manevich ◽  
E. N. Kamnev
Keyword(s):  
Radioactive Waste ◽  
System Analysis ◽  
Radioactive Waste Disposal ◽  
Energy Concentration ◽  
Geological Environment ◽  
Tectonic Structures ◽  
High Level Radioactive Waste ◽  
The Stability ◽  
High Level

This article describes the methodological aspects and some results of the assessment and prediction of the geodynamic stability of the geological environment as applied to the problem of ensuring the safety of underground isolation of high-level radioactive waste (HLRW) in the geological formations of the Nizhnekansky massif, Krasnoyarsk Region. For this, the authors introduced a basic concept of the stability of the geological environment. Based on instrumental observations, mathematical models, system analysis of geospatial data, the ranking of structural tectonic blocks according to the degree of stability and the geodynamic zoning of the northern part of the Nizhnekansky massif were implemented. To assess the stability, the authors used geological data, a digital elevation model, the results of the interpretation of geophysical fields and geodetic observations. It is shown that the stability of the blocks differs significantly according to kinematic parameters. Geodetic observations based on GPS/GLONASS satellite systems, carried out in 2010-2019, made it possible to obtain for the first time information on the rates of horizontal movements of the lithosphere and their cyclicity for the region located in the zone of force interaction of the largest tectonic structures, namely, Siberian platform, West Siberian plate and the Altai-Sayan Orogen. The maximum speeds were recorded for points located in the zone of dynamic influence of the Muratovsky and Pravoberezhny faults. The energy concentration criteria as the fracturability characteristics of structural rock blocks are proposed for the stress–strain analysis of rock mass. To substantiate the long-term geodynamic safety of deep disposals of HLRW of the 1st and 2nd classes, the authors developed a program for the long-term observations of differentiated movements in the earth’s crust and seismic activity for 2021–2026 in an underground research laboratory. The study was carried out under the state contract between the Geophysical Center of the Russian Academy of Sciences and the Ministry of Science and Higher Education of the Russian Federation.

scholarly journals Influence of Thermomechanical Treatments on Corrosion of Carbon Steel in Synthetic Geopolymer Fly Ash Pore Solution

2021 ◽  
Vol 11 (9) ◽  
pp. 4054
Author(s):  
Juan Bosch ◽  
Ulises Martin ◽  
Jacob Ress ◽  
Keston Klimek ◽  
David M. Bastidas
Keyword(s):  
Fly Ash ◽  
Carbon Steel ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Pore Solution ◽  
Concrete Experience ◽  
Cyclic Potentiodynamic Polarization ◽  
The Stability ◽  
Bainite Microstructure ◽  
Charge Transfer Coefficient

In this study the effect of thermomechanical treatments in chloride induced pitting corrosion is presented for carbon steel rebars exposed to synthetic fly ash (FA) pore solution. Due to the likely phase transformations that steel reinforcements in concrete experience during the event of a fire, the understanding of the corrosion behavior of such phases is key in predicting the stability of the structure. The motivation for this study arrives from the scarce literature regarding the corrosion behavior of thermomechanically treated steel reinforcements in FA environments and the need for further investigation to understand its mechanism. In order to better understand the effects on the corrosion behavior electrochemical measurements including cyclic potentiodynamic polarization curves (CPP) and electrochemical impedance spectroscopy (EIS) were used. It was found that quenched specimens showed enhanced corrosion kinetics as their icorr values were higher, being of 3.18 × 10−5 and 2.20 × 10−5 A/cm2 for water and oil quenched compared to 2.13 × 10−6 A/cm2 for the as-received. Furthermore, the effective capacitance of the double layer (Ceff,dl) showed the lower stability of the passive film for the quenched specimens, with values of 1.11 × 10−3 µF/cm2 for the as-receive sample that decreased to 8.12 × 10−4 µF/cm2 for the water quenched sample. The anodic charge transfer coefficient in the synthetic FA alkaline pore solution changes from 0.282 to 0.088, for the as-received and water quenched rebars specimens, respectively. These results indicate a lower energy barrier for the anodic dissolution reaction of quenched specimens, indicating that martensite and bainite microstructures promote corrosion process. Enhanced corrosion was found on quenched samples presenting martensite and bainite microstructure as showed by the increased pith depth, with values of 5 μm compared to 1 μm observed in the as-received samples.

scholarly journals Corrosion Behavior of Some Timonb Alloys in Ringer Solution

2020 ◽  
Vol 71 (7) ◽  
pp. 187-196
Author(s):  
Maria Magdalena Pricopi ◽  
Romeu Chelariu ◽  
Nicolae Apostolescu ◽  
Doina-Margareta Gordin ◽  
Daniel Sutiman ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Immersion Time ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Electrochemical Techniques ◽  
Ringer Solution ◽  
Open Circuit ◽  
Chemical Compositions ◽  
Solution Ph

The aim of this study was to investigate the influence of different process parameters as chemical composition, the pH value and immersion time on the corrosion of the some TiMoNb alloys, using different electrochemical techniques such as: cyclic voltammetry, open circuit potential (OCP) measurement, polarization curves and electrochemical impedance spectroscopy (EIS). The alloys were analyzed in the natural pH of the Ringer solution, but also with an acidic modification of the solution (ph = 4) and a basic modification (ph = 8). The more acidic values of pH, the more evident are differences between corrosion behavior of titanium-based alloys depending on their chemical compositions and immersion times.

scholarly journals Electrophoresis Assembly of Novel Superhydrophobic Molybdenum Trioxide (MoO3) Films with Great Stability

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 336 ◽  
Author(s):  
Xiaogang Guo ◽  
Taotao Liang
Keyword(s):  
Molybdenum Trioxide ◽  
Film Formation ◽  
Normal Pressure ◽  
Chemical Compositions ◽  
Great Resistance ◽  
X Ray ◽  
Oxide Powders ◽  
High Efficient ◽  
Assembly Technique ◽  
The Stability

This work presents a hydrothermal synthesis approach to produce novel schistose molybdenum trioxide (MoO3) powders with wide application, and introduces a facile electrophoresis assembly technique to construct the superhydrophobic MoO3 films (SMFs) with contact angle up to 169 ± 1° at normal pressure and temperature. The microstructures and chemical compositions of product were analyzed by field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD). The wettability and stability studies indicate that the SMFs all show great resistance in various environments with adjusting factors, including droplets with different surface tension, pH, relative humidity, etc., and the stability can be maintained at least for five months. Notably, this paper will provides a valuable reference for designing novel oxide powders and their high-efficient hydrophobic film formation with self-cleaning or water proof properties.

scholarly journals Penentuan Parameter Rangkak pada Bentonit sebagai Bahan Penyangga (Buffer Material) dengan Uji Geser Langsung

2019 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Arintha I.D. Syafiarti ◽  
Huang Wei-Hsing ◽  
Chung Chih- Chung
Keyword(s):  
Strain Rate ◽  
Radioactive Waste Disposal ◽  
Test Results ◽  
Buffer Material ◽  
Angular Strain ◽  
Long Time ◽  
Dependent Strain ◽  
Preliminary Research ◽  
The Stability ◽  
High Level

A preliminary research to investigate the creep behavior of bentonite as buffer material in a high-level nuclear or radioactive waste disposal hole as bentonite needs to maintain the stability of the waste canister for a long time, to avoid the displacement caused by the weight of the canister itself and the thermal, hydrological, mechanical and chemical (THM-C) processes of the near filed. The increase of bentonite time-dependent strain or creep needs to be taken into account for the safety of the disposal hole. The creep parameters obtained from the angular strain rate equation, through stress-controlled direct shear test using compacted SPV200 bentonite samples. The test results show an increase in angular strain rate with increasing of the applied stress.

Corrosion Behavior of The Weld Zone of Carbon Steel Overpack for HLW Geological Disposal

2008 ◽  
Author(s):  
Yutaka Yokoyama ◽  
Rieko Takahashi ◽  
Hidekazu Asano ◽  
Naoki Taniguchi ◽  
Morimasa Naito
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Weld Zone ◽  
Geological Disposal
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