scholarly journals Isotopic tracing of hydrogen transport and trapping in nuclear materials

2017 ◽  
Vol 375 (2098) ◽  
pp. 20160406 ◽  
Author(s):  
Jacques Chêne ◽  
Frantz Martin
Keyword(s):  
Hydrogen Embrittlement ◽  
Point Defects ◽  
Stress Corrosion Cracking ◽  
Hydrogen Absorption ◽  
Hydrogen Desorption ◽  
Nuclear Materials ◽  
Hydrogen Transport ◽  
Transport Mechanisms ◽  
Isotopic Tracing

Some illustrations of the use of deuterium or tritium for isotopic tracing of hydrogen absorption, transport and trapping in nuclear materials are presented. Isotopic tracing of hydrogen has been shown to be successful for the determination of the boundaries conditions for hydrogen desorption or absorption in a material exposed to a hydrogen source. Also, the unique capabilities of isotopic tracing and related techniques to characterize H interactions with point defects and dislocations acting as moving traps has been demonstrated. Such transport mechanisms are considered to play a major role in some stress corrosion cracking and hydrogen embrittlement mechanisms. This article is part of the themed issue ‘The challenges of hydrogen and metals’.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

Observations of Damage and Transport of Hydrogen in Ion Bombarded Polycrystalline Silicon

1984 ◽  
Vol 33 ◽  
Author(s):  
D. J. Sharp ◽  
J. K. G. Panitz ◽  
C. H. Seager
Keyword(s):  
Polycrystalline Silicon ◽  
Ion Beam ◽  
Columnar Structure ◽  
Hydrogen Transport ◽  
Transport Mechanisms ◽  
Sheet Resistivity ◽  
Near Surface ◽  
Resistivity Measurements ◽  
Transmission Electron ◽  
Defect Passivation

ABSTRACTA combination of chemical etching and sheet resistivity measurements showed that intense (1.4 mA/cm2 ) low energy (1400 eV) ion beam hydrogenation of polycrystalline silicon having a columnar structure can produce electrical defect passivation to depths in the order of 100 μm. Transmission electron micrographs disclose surface and near-surface features resulting from the ion beam bombardment which suggest that one of the hydrogen transport mechanisms may be defect induced.

Hydrogen Transport and Hydrogen-Assisted Cracking in SUS304 Stainless Steel During Deformation at Low Temperatures

2015 ◽  
Author(s):  
Lin Zhang ◽  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Room Temperature ◽  
Hydrogen Release ◽  
Hydrogen Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Strain Induced Martensite ◽  
Hydrogen Assisted Cracking ◽  
Slip Planes

The behaviors of hydrogen transport and hydrogen-assisted cracking in hydrogen-precharged SUS304 austenitic stainless steel sheets in a temperature range from 177 to 298 K are investigated by a combined tensile and hydrogen release experiment as well as magnetic force microscopy (MFM) based on atomic force microscopy (AFM). It is observed that the hydrogen embrittlement increases with decreasing temperature, reaches a maximum at around 218 K, and then decreases with further temperature decrease. The hydrogen release rate increases with increasing strain until fracture at room temperature but remains near zero level at and below 218 K except for some small distinct release peaks. The MFM observations reveal that fracture occurs at phase boundaries along slip planes at room temperature and twin boundaries at 218 K. The role of strain-induced martensite in the hydrogen transport and hydrogen embrittlement is discussed.

On the Characterisatiopn of Order-Disorder in Ion-Irradiated Pyrochlore Compounds by Electron Scattering Methods

2008 ◽  
Vol 1122 ◽  
Author(s):  
Gregory R. Lumpkin ◽  
Karl R. Whittle ◽  
Mark G. Blackford ◽  
Katherine L. Smith ◽  
Nestor J. Zaluzec
Keyword(s):  
Electron Scattering ◽  
Diffuse Scattering ◽  
Zone Axis ◽  
Irradiation Damage ◽  
Nuclear Materials ◽  
Crystalline Fraction ◽  
Selected Area Electron Diffraction ◽  
Pyrochlore Compounds ◽  
Diffraction Patterns

AbstractSelected area electron diffraction patterns are routinely used to determine the effects of irradiation damage in nuclear materials. Using zone axis orientations, the intensities of Bragg beams change from a dynamical to kinematic-like state due to the presence of amorphous domains in the material. Such changes in beam intensities, together with the increased diffuse scattering from the increasing amorphous fraction, present a major obstacle to the determination of cation or anion disorder in the crystalline fraction.

scholarly journals POTENTIAL MITIGATION STRATEGIES FOR PREVENTING STRESS CORROSION CRACKING FAILURES IN HIGH-BURNUP CANDU FUEL

2018 ◽  
Vol 7 (2) ◽  
pp. 127-146 ◽  
Author(s):  
Markus Piro ◽  
Dion Sunderland ◽  
Winston Revie ◽  
Steve Livingstone ◽  
Ike Dimayuga ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Lessons Learned ◽  
Mitigation Strategies ◽  
Nuclear Materials ◽  
Characterization Methods ◽  
Candu Reactors ◽  
High Degree ◽  
Fuel Doping

Potential mitigation strategies for preventing stress corrosion cracking (SCC) failures in CANDU fuel cladding that are based on lessons learned on both domestic and international fronts are discussed in this paper. Although SCC failures have not been a major concern in CANDU reactors in recent decades, they may resurface at higher burnup for conventional fuels or with nonconventional fuels that are currently being investigated, such as MOX or thoria-based fuels. The motivation of this work is to provide the foundation for considering possible remedies for SCC failures. Three candidate remedies are discussed, namely improved fabrication methods for fuel appendages, barrier-liner cladding, and fuel doping. In support of this effort, recent advances in experimental characterization methods are described—methods that have been successfully used in non-nuclear materials that can be used to further elucidate SCC behaviour in CANDU fuel. The overall objective is to outline a path forward for characterizing material behaviour as an essential part of investigating remedies to SCC failure. This will allow increased fuel discharge burnup, maximum linear power, and plant manoeuvrability, while maintaining a high degree of reliability.

scholarly journals Stress Corrosion Cracking of Additively Manufactured Alloy 625

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6115
Author(s):  
Marina Cabrini ◽  
Sergio Lorenzi ◽  
Cristian Testa ◽  
Francesco Carugo ◽  
Tommaso Pastore ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hydrogen Embrittlement ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strain ◽  
Corrosion Cracking ◽  
Slow Strain Rate ◽  
Laser Source ◽  
Alloy 625

Laser bed powder fusion (LPBF) is an additive manufacturing technology for the fabrication of semi-finished components directly from computer-aided design modelling, through melting and consolidation, layer upon layer, of a metallic powder, with a laser source. This manufacturing technique is particularly indicated for poor machinable alloys, such as Alloy 625. However, the unique microstructure generated could modify the resistance of the alloy to environment assisted cracking. The aim of this work was to analyze the stress corrosion cracking (SCC) and hydrogen embrittlement resistance behavior of Alloy 625 obtained by LPBF, both in as-built condition and after a standard heat treatment (grade 1). U-bend testing performed in boiling magnesium chloride at 155 and 170 °C confirmed the immunity of the alloy to SCC. However, slow strain rate tests in simulated ocean water on cathodically polarized specimens highlighted the possibility of the occurrence of hydrogen embrittlement in a specific range of strain rate and cathodic polarization. The very fine grain size and dislocation density of the thermally untreated specimens appeared to increase the hydrogen diffusion and embrittlement effect on pre-charged specimens that were deformed at the high strain rate. Conversely, heat treatment appeared to mitigate hydrogen embrittlement at high strain rates, however at the slow strain rate all the specimens showed a similar behavior.

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