Displacive and Diffusional Transformations of the Beta Phase in Zirconium Alloys

2014 ◽  
pp. 23-51 ◽  
Author(s):  
S. Banerjee
Keyword(s):  
Zirconium Alloys ◽  
Beta Phase

Oxygen, Hydrogen and Main Alloying Chemical Elements Partitioning Upon Alpha←→Beta Phase Transformation in Zirconium Alloys

2011 ◽  
Vol 172-174 ◽  
pp. 753-759 ◽  
Author(s):  
Jean Christophe Brachet ◽  
Caroline Toffolon-Masclet ◽  
Didier Hamon ◽  
Thomas Guilbert ◽  
Gwenaël Trego ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Zirconium Alloys ◽  
Beta Phase ◽  
Nuclear Microprobe ◽  
Light Water Reactors ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
Alpha Beta ◽  
Water Reactors

Due to their adequate properties, zirconium alloys are the reference materials for the nuclear fuel cladding tubes of Light Water Reactors (LWR). During some hypothetical accidental High Temperature (HT) transients, the materials should experience heavy steam oxidation and deep metallurgical evolutions. This promotes Alpha-Beta phase transformations and an associated strong partitioning of oxygen/hydrogen and of the main chemical alloying elements (Nb, Sn, Fe and Cr). Moreover, it has been shown quite recently that such chemical elements partitioning during on-cooling Beta-to-Alpha transformation can strongly impact the residual mechanical properties of HT oxidized materials. Thus, it appeared that it was important to better quantify and, if possible, to compute the quite complex phase equilibrium that occurs in multi-alloyed zirconium materials in the presence of both oxygen and hydrogen. For that, systematic studies have been performed on industrial alloys, charged with oxygen and/or hydrogen. After applying different heating/cooling scenarii, both Electron Microprobe using Wave Dispersive Spectrometry (WDS) and Nuclear Microprobe using Elastic Recoil Detection Analysis (ERDA) have been applied. Finally, to support the observed chemical elements partitioning between the Alpha and Beta allotropic phases, some thermodynamic calculations have been performed thanks to the development and the use of a specific thermodynamic database for zirconium alloys called “Zircobase".

Control of hydrogen absorption by nickel films obtained upon magnetic spraying of zirconium alloy using the thermoEMF method

2020 ◽  
Vol 86 (8) ◽  
pp. 32-37
Author(s):  
V. V. Larionov ◽  
Xu Shupeng ◽  
V. N. Kudiyarov
Keyword(s):  
Magnetron Sputtering ◽  
Hydrogen Concentration ◽  
Hydrogen Absorption ◽  
Zirconium Alloy ◽  
Hydrogen Adsorption ◽  
Zirconium Alloys ◽  
Nickel Film ◽  
Protective Film ◽  
Nickel Films ◽  
Hydrogen Penetration

Nickel films formed on the surface of zirconium alloys are often used to protect materials against hydrogen penetration. Hydrogen adsorption on nickel is faster since the latter actively interacts with hydrogen, oxidizes and forms a protective film. The goal of the study is to develop a method providing control of hydrogen absorption by nickel films during vacuum-magnetron sputtering and hydrogenation via measuring thermoEMF. Zirconium alloy E110 was saturated from the gas phase with hydrogen at a temperature of 350°C and a pressure of 2 atm. A specialized Rainbow Spectrum unit was used for coating. It is shown that a nickel film present on the surface significantly affects the hydrogen penetration into the alloy. A coating with a thickness of more than 2 μm deposited by magnetron sputtering on the surface of a zirconium alloy with 1% Nb, almost completely protects the alloy against hydrogen penetration. The magnitude of thermoemf depends on the hydrogen concentration in the zirconium alloy and film thickness. An analysis of the hysteresis width of the thermoEMF temperature loop and a method for determining the effective activation energy of the conductivity of a hydrogenated material coated with a nickel film are presented. The results of the study can be used in assessing the hydrogen concentration and, hence, corrosion protection of the material.

Typical Zirconium Alloys Microstructures in Nuclear Components

2014 ◽  
Vol 51 (9) ◽  
pp. 656-674 ◽  
Author(s):  
A. V. Flores ◽  
A. G. Gomez ◽  
G. A. Juarez ◽  
N. Loureiro ◽  
R. I. Samper ◽  
...  
Keyword(s):  
Zirconium Alloys

Fundamental Studies of Beta Phase Decomposition Modes in Titanium Alloys.

1988 ◽  
Author(s):  
H. I. Aaronson ◽  
A. M. Dalley ◽  
T. Furuhara ◽  
Y. Mou
Keyword(s):  
Titanium Alloys ◽  
Beta Phase ◽  
Phase Decomposition

Fundamental Studies of Beta Phase Decomposition Modes in Titanium Alloys

1990 ◽  
Author(s):  
H. I. Aaronson ◽  
Y. Mou ◽  
M. G. Hall
Keyword(s):  
Titanium Alloys ◽  
Beta Phase ◽  
Phase Decomposition

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling

Zirconium and zirconium alloys

2008 ◽  
Author(s):  
H. G. Spilker ◽  
Roman Bender
Keyword(s):  
Zirconium Alloys

Simulation of ductile fracture of zirconium alloys based on triaxiality dependent cohesive zone model

2021 ◽  
Author(s):  
C. Fang ◽  
X. Guo ◽  
G. J. Weng ◽  
J. H. Li ◽  
G. Chen
Keyword(s):  
Ductile Fracture ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Zirconium Alloys ◽  
Zone Model

scholarly journals Evidence of hydrogen trapping at second phase particles in zirconium alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher Jones ◽  
Vidur Tuli ◽  
Zaheen Shah ◽  
Mhairi Gass ◽  
Patrick A. Burr ◽  
...  
Keyword(s):  
Density Functional ◽  
Secondary Ion Mass Spectrometry ◽  
Zirconium Alloys ◽  
Nuclear Industry ◽  
Second Phase ◽  
Hydrogen Trapping ◽  
Functional Theory ◽  
Second Phase Particles ◽  
Hydrogen Isotope Ratios ◽  
Dft Modelling

AbstractZirconium alloys are used in safety–critical roles in the nuclear industry and their degradation due to ingress of hydrogen in service is a concern. In this work experimental evidence, supported by density functional theory modelling, shows that the α-Zr matrix surrounding second phase particles acts as a trapping site for hydrogen, which has not been previously reported in zirconium. This is unaccounted for in current models of hydrogen behaviour in Zr alloys and as such could impact development of these models. Zircaloy-2 and Zircaloy-4 samples were corroded at 350 °C in simulated pressurised water reactor coolant before being isotopically spiked with 2H2O in a second autoclave step. The distribution of 2H, Fe and Cr was characterised using nanoscale secondary ion mass spectrometry (NanoSIMS) and high-resolution energy dispersive X-ray spectroscopy. 2H− was found to be concentrated around second phase particles in the α-Zr lattice with peak hydrogen isotope ratios of 2H/1H = 0.018–0.082. DFT modelling confirms that the hydrogen thermodynamically favours sitting in the surrounding zirconium matrix rather than within the second phase particles. Knowledge of this trapping mechanism will inform the development of current understanding of zirconium alloy degradation through-life.

scholarly journals Solid state phase transformation kinetics in Zr-base alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. R. Massih ◽  
Lars O. Jernkvist
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Zirconium Alloys ◽  
Excess Oxygen ◽  
Transformation Kinetics ◽  
Fuel Cladding ◽  
Reactor Accident ◽  
Phase Transformation Kinetics ◽  
Solid State Phase Transformation ◽  
Water Reactors

AbstractWe present a kinetic model for solid state phase transformation ($$\alpha \rightleftharpoons \beta$$ α ⇌ β ) of common zirconium alloys used as fuel cladding material in light water reactors. The model computes the relative amounts of $$\beta$$ β or $$\alpha$$ α phase fraction as a function of time or temperature in the alloys. The model accounts for the influence of excess oxygen (due to oxidation) and hydrogen concentration (due to hydrogen pickup) on phase transformation kinetics. Two variants of the model denoted by A and B are presented. Model A is suitable for simulation of laboratory experiments in which the heating/cooling rate is constant and is prescribed. Model B is more generic. We compare the results of our model computations, for both A and B variants, with accessible experimental data reported in the literature covering heating/cooling rates of up to 100 K/s. The results of our comparison are satisfactory, especially for model A. Our model B is intended for implementation in fuel rod behavior computer programs, applicable to a reactor accident situation, in which the Zr-based fuel cladding may go through $$\alpha \rightleftharpoons \beta$$ α ⇌ β phase transformation.

Sign in / Sign up

Export Citation Format

Share Document