TY - JOUR
T1 - Effect of external stress on deuteride (hydride) precipitation in Zircaloy-4 using in situ neutron diffraction
AU - Lin, Jun li
AU - An, Ke
AU - Stoica, Alexandru D.
AU - Heuser, Brent J.
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/4/15
Y1 - 2017/4/15
N2 - In situ neutron diffraction is utilized to study the deuteride (hydride) precipitation behavior in a cold-worked stress-relieved (CWSR) Zircaloy-4 material upon cooling from 420 °C to room temperature with a 78 MPa external stress applied along the rolling direction (RD) of the material. Two banks detector capture the diffraction signal from two principal directions of the specimen, the normal direction (ND) and the rolling direction (RD). The evolution of deuterium concentration in zirconium solid solution along the two specimen directions is measured by studying the δ-(220) peak intensity, applying the Rietveld refinement method to the diffraction data and using the measured zirconium c-axis lattice distortion. The deuterium concentration is observed to be higher for zirconium grains in the ND than the RD. The terminal solid solubility of precipitation (TSSp) for deuterium in the solution is then described using the Arrhenius equation. It is observed that the applied stress reduces the energy term Q in the Arrhenius equation when compared with the unstressed Q values from the work of others. A model by Puls is applied to study the effect of stress on deuterium solubility, with polycrystalline hydride precipitation strain calculated using the Kearns factor representative of the studied material. The experimental result does not agree with the model prediction of Puls.
AB - In situ neutron diffraction is utilized to study the deuteride (hydride) precipitation behavior in a cold-worked stress-relieved (CWSR) Zircaloy-4 material upon cooling from 420 °C to room temperature with a 78 MPa external stress applied along the rolling direction (RD) of the material. Two banks detector capture the diffraction signal from two principal directions of the specimen, the normal direction (ND) and the rolling direction (RD). The evolution of deuterium concentration in zirconium solid solution along the two specimen directions is measured by studying the δ-(220) peak intensity, applying the Rietveld refinement method to the diffraction data and using the measured zirconium c-axis lattice distortion. The deuterium concentration is observed to be higher for zirconium grains in the ND than the RD. The terminal solid solubility of precipitation (TSSp) for deuterium in the solution is then described using the Arrhenius equation. It is observed that the applied stress reduces the energy term Q in the Arrhenius equation when compared with the unstressed Q values from the work of others. A model by Puls is applied to study the effect of stress on deuterium solubility, with polycrystalline hydride precipitation strain calculated using the Kearns factor representative of the studied material. The experimental result does not agree with the model prediction of Puls.
KW - Deuterium (hydrogen) solubility
KW - Neutron diffraction
KW - Zirconium alloys
KW - Zirconium deuteride (hydride)
UR - http://www.scopus.com/inward/record.url?scp=85014232547&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2017.01.042
DO - 10.1016/j.jnucmat.2017.01.042
M3 - Article
AN - SCOPUS:85014232547
SN - 0022-3115
VL - 487
SP - 396
EP - 405
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -