scholarly journals H2 PERMEATION BEHAVIOR OF Cr2AlC AND Ti2AlC MAX PHASE COATED ZIRCALOY-4 BY NEUTRON RADIOGRAPHY

2018 ◽  
Vol 58 (1) ◽  
pp. 69 ◽  
Author(s):  
Chongchong Tang ◽  
Mirco Karl Grosse ◽  
Pavel Trtik ◽  
Martin Steinbrück ◽  
Michael Stüber ◽  
...  
Keyword(s):  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Neutron Radiography ◽  
Zirconium Alloys ◽  
Hydrogen Uptake ◽  
Hydrogen Release ◽  
Max Phase ◽  
Normal Operation ◽  
Temperature Oxidation ◽  
Design Basis

Hydrogen uptake by nuclear fuel claddings during normal operation as well as loss of coolant during design basis and severe accidents beyond design basis has a high safety relevance because hydrogen degrade the mechanical properties of the zirconium alloys applied as cladding material. Currently, claddings with enhanced accident tolerance are under development. One group of such accident tolerant fuel (ATF) claddings are zirconium alloys with surface coatings reducing corrosion and high-temperature oxidation rate, as well as the chemical heat and hydrogen release during hypothetical accidents. The hydrogen permeation through the coating is an important parameter ensuring material safety. In this work, the hydrogen permeation of Ti2AlC and Cr2AlC MAX phase coatings on Zircaloy-4 is investigated by means of neutron radiography. Both coatings are robust hydrogen diffusion barriers that effectively suppress hydrogen permeation into the matrix.

scholarly journals In Situ Neutron Radiography Investigations of Hydrogen Related Processes in Zirconium Alloys

2021 ◽  
Vol 11 (13) ◽  
pp. 5775
Author(s):  
Mirco Grosse ◽  
Burkhardt Schillinger ◽  
Anders Kaestner
Keyword(s):  
Zirconium Alloy ◽  
High Temperature Oxidation ◽  
Hydrogen Diffusion ◽  
Neutron Radiography ◽  
Zirconium Alloys ◽  
Hydrogen Uptake ◽  
Temperature Oxidation ◽  
Diffusive Processes ◽  
Kinetics Of

In situ neutron radiography experiments can provide information about diffusive processes and the kinetics of chemical reactions. The paper discusses requirements for such investigations. As examples of the zirconium alloy Zircaloy-4, the hydrogen diffusion, the hydrogen uptake during high-temperature oxidation in steam, and the reaction in nitrogen/steam and air/steam atmospheres, results of in situ neutron radiography investigations are reviewed, and their benefit is discussed.

Ex-situ and in-situ Neutron Radiography Investigations of the Hydrogen Uptake of Nuclear Fuel Cladding Materials During Steam Oxidation at 1000°C and Above

2010 ◽  
Vol 1262 ◽  
Author(s):  
Mirco Grosse ◽  
Marius van den Berg ◽  
Eberhard Helmar Lehmann ◽  
Burkhard Schillinger
Keyword(s):  
Hydrogen Diffusion ◽  
Neutron Radiography ◽  
Zirconium Alloys ◽  
Hydrogen Uptake ◽  
Steam Oxidation ◽  
Ex Situ ◽  
In Situ Experiments ◽  
Nuclear Fuel Cladding ◽  
Non Destructive

AbstractNeutron radiography is a powerful tool for the investigation of the hydrogen uptake of zirconium alloys. It is fast, fully quantitative, non-destructive and provides a spatial resolution of 30 μm. The non-destructive character of neutron radiography provides the possibility of in-situ investigations. The paper describes the calibration of the method and delivers results of ex-situ measurements of the hydrogen concentration distribution after steam oxidation, as well as in-situ experiments of hydrogen diffusion in β-Zr and in-situ investigations of the hydrogen uptake during steam oxidation.

scholarly journals Effect of Cold-Rolled Thickness Reduction Degree on Characteristics of Hydrogen Diffusion in Silicon Steel

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Yongfeng Li ◽  
Lian Cai ◽  
Guanjun Liu ◽  
Lijie Ma
Keyword(s):  
Current Density ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Hydrogen Uptake ◽  
Silicon Steel ◽  
Thickness Reduction ◽  
Reduction Degree ◽  
Charging Current ◽  
Cold Rolled ◽  
Cathodic Charging

The characteristic of hydrogen uptake and diffusion in the cold-rolled silicon steel was investigated by electrochemical hydrogen permeation technique performed under different cathodic charging current density and cold-rolled thickness reduction degree. The results indicated that anodic permeation current density increased with increasing cathodic charging current for the specimens. Moreover, the anodic steady state permeation current density and the solubility increased with an increase in the cold-rolled thickness reduction degrees. The breakthrough time of hydrogen in the specimens was shortened with increasing thickness reduction degrees, and the value of the hydrogen diffusivity decreased gradually with increasing thickness reduction degrees.

In-situ-determination of tribologically induced hydrogen permeation using electrochemical methods

2019 ◽  
Vol 234 (7) ◽  
pp. 1027-1034
Author(s):  
Natalie Oberle ◽  
Tobias Amann ◽  
Dominik Kürten ◽  
Rahul Raga ◽  
Andreas Kailer
Keyword(s):  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Normal Load ◽  
Hydrogen Release ◽  
Enhanced Diffusion ◽  
Lubricant Composition ◽  
Hydrogen Penetration ◽  
Bearing Damage

White etching cracks are one of the possible causes of bearing damage, which can lead to the failure of wind turbines. The mechanisms of hydrogen diffusion in bearings are not yet fully understood, but it is assumed under tribological loading that the lubricant degradation releases hydrogen which diffuses into the contacting surfaces (i.e. steel). This leads to hydrogen-induced cracking and damage to the bearings. In order to better understand these mechanisms, it is necessary to investigate the influence of tribological loads and lubricant composition on hydrogen release. For this purpose, a test setup was developed for the analysis of tribologically induced hydrogen permeation by means of a ball-on-plate test. The diffused hydrogen was measured with an electrochemical three-electrode setup. The results showed a direct correlation between the amount of hydrogen released and the applied normal load. Furthermore, an increased velocity resulted in enhanced diffusion of hydrogen through metal. In addition, the tribological contact surface was decisive for hydrogen permeation. The higher velocity and the larger contact area result in an activated nascent iron surface which promotes hydrogen penetration. The results show that lubricants can be classified as critical for the formation of hydrogen embrittlement in tribological contacts.

High Temperature Oxidation of Polycrystalline Diamond Coated Zirconium Alloy

2016 ◽  
Author(s):  
Jan Škarohlíd ◽  
Radek Škoda ◽  
Irena Kratochvílová
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Zirconium Alloy ◽  
High Temperature Oxidation ◽  
Polycrystalline Diamond ◽  
Zirconium Alloys ◽  
Hydrogen Release ◽  
Primary Circuit ◽  
Temperature Oxidation ◽  
Diamond Layer

Polycrystalline diamond coating is a promising possibility for prevention, or reduction of high temperature oxidation of zirconium alloys and decrease corrosion rate of zirconium alloy during standard operation. Zirconium alloys are widely used as cladding and construction material in almost all types of nuclear reactors, where usually creates a barrier between nuclear fuel and cooling water in the primary circuit. Hydrogen and considerable amount of heat is released during steam oxidation that may occur in an eventual accident. In this paper zirconium alloy was covered by polycrystalline diamond layer using Plasma Enhanced Linear Antennas Microwave Chemical Vapor Deposition system reactor. X-Ray Diffraction and Raman spectroscopy measurements confirmed coverage of the surface area with crystalline and amorphous carbon layer. Characterizations (Raman spectroscopy) were done for zirconium alloy covered with polycrystalline diamond layer before and after high temperature steam exposure. Weight increase and hydrogen release ware measured during steam exposure.

Quantification of hydrogen uptake of steam-oxidized zirconium alloys by means of neutron radiography

2008 ◽  
Vol 20 (10) ◽  
pp. 104263 ◽  
Author(s):  
M Grosse ◽  
G Kuehne ◽  
M Steinbrueck ◽  
E Lehmann ◽  
J Stuckert ◽  
...  
Keyword(s):  
Neutron Radiography ◽  
Zirconium Alloys ◽  
Hydrogen Uptake ◽  
Oxidized Zirconium

Parameters Influencing the Secondary Hydrogenation of Zr-Sn and Zr-Nb Alloys During Steam Oxidation Under LOCA and Severe Accident Conditions

2010 ◽  
Author(s):  
Mirco K. Grosse ◽  
Martin Steinbrueck ◽  
Juri Stuckert
Keyword(s):  
Oxide Layer ◽  
Large Scale ◽  
Gas Flow ◽  
Hydrogen Diffusion ◽  
Neutron Radiography ◽  
Hydrogen Uptake ◽  
Experimental Results ◽  
Steam Oxidation ◽  
Severe Accident

The parameters influencing secondary hydrogen uptake can be divided into two groups: material properties and process parameters. The first group includes for instance the steam oxidation kinetics, the oxide morphology and the hydrogen diffusion through the oxide layer. The second group covers for instance the temperature, the total pressure, the gas flow type and rates, the cladding area and the filling of the rods. Together with a theoretical view on the influence of different parameters on the hydrogen uptake of zirconium alloys experimental results from separate-effect tests, large-scale QUENCH tests and in-situ neutron radiography investigations of the hydrogen uptake during steam oxidation will be presented. The hydrogen concentrations in specimens made from commonly used cladding materials were determined by quantitative analysis of neutron radiographs. Information obtained from ex- and in-situ steam oxidation experiments will be given. The presentation of the experimental results will be focused on the influence of oxidation time and temperature, of the oxide layer morphology, the sample geometry and of the gas flow rates on the hydrogen concentration of the remaining metal phases. Differences between Zr-Sn, Zr-Nb and Zr-Sn-Nb alloys will be discussed.

scholarly journals Investigation of the Pressure Dependent Hydrogen Solubility in a Martensitic Stainless Steel Using a Thermal Agile Tubular Autoclave and Thermal Desorption Spectroscopy

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 231
Author(s):  
Patrick Fayek ◽  
Sebastian Esser ◽  
Vanessa Quiroz ◽  
Chong Dae Kim
Keyword(s):  
Stainless Steel ◽  
Thermal Desorption ◽  
Hydrogen Diffusion ◽  
Martensitic Stainless Steel ◽  
Thermal Desorption Spectroscopy ◽  
Hydrogen Uptake ◽  
Hydrogen Solubility ◽  
Automotive Components ◽  
Set Up ◽  
Service Application

Hydrogen is nowadays in focus as an energy carrier that is locally emission free. Especially in combination with fuel-cells, hydrogen offers the possibility of a CO2 neutral mobility, provided that the hydrogen is produced with renewable energy. Structural parts of automotive components are often made of steel, but unfortunately they may show degradation of the mechanical properties when in contact with hydrogen. Under certain service conditions, hydrogen uptake into the applied material can occur. To ensure a safe operation of automotive components, it is therefore necessary to investigate the time, temperature and pressure dependent hydrogen uptake of certain steels, e.g., to deduct suitable testing concepts that also consider a long term service application. To investigate the material dependent hydrogen uptake, a tubular autoclave was set-up. The underlying paper describes the set-up of this autoclave that can be pressurised up to 20 MPa at room temperature and can be heated up to a temperature of 250 °C, due to an externally applied heating sleeve. The second focus of the paper is the investigation of the pressure dependent hydrogen solubility of the martensitic stainless steel 1.4418. The autoclave offers a very fast insertion and exertion of samples and therefore has significant advantages compared to commonly larger autoclaves. Results of hydrogen charging experiments are presented, that were conducted on the Nickel-martensitic stainless steel 1.4418. Cylindrical samples 3 mm in diameter and 10 mm in length were hydrogen charged within the autoclave and subsequently measured using thermal desorption spectroscopy (TDS). The results show how hydrogen sorption curves can be effectively collected to investigate its dependence on time, temperature and hydrogen pressure, thus enabling, e.g., the deduction of hydrogen diffusion coefficients and hydrogen pre-charging concepts for material testing.

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