THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS
Within the framework of the delayed hydride cracking phenomena reported for the pressure tubes of CANDU-typenuclear reactors, we study the influence of the Zr-β(∼20 %Nb -∼80 %Zr) continuous phase on the hydrogen diffusion coefficient,DH, through the Zr-α/ Zr-βbiphasic alloy. We propose an improved p...
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| Format: | Article |
| Language: | Spanish |
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CEILAP-UNIDEF-CONICET-CITEDEF
2022-01-01
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| Series: | Anales (Asociación Física Argentina) |
| Subjects: | |
| Online Access: | https://anales.fisica.org.ar/index.php/analesafa/article/view/2304/2733 |
| _version_ | 1797739301744672768 |
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| author | G. Beltramo V. P. Ramunni R. C. Pasianot |
| author_facet | G. Beltramo V. P. Ramunni R. C. Pasianot |
| author_sort | G. Beltramo |
| collection | DOAJ |
| description | Within the framework of the delayed hydride cracking phenomena reported for the pressure tubes of CANDU-typenuclear reactors, we study the influence of the Zr-β(∼20 %Nb -∼80 %Zr) continuous phase on the hydrogen diffusion coefficient,DH, through the Zr-α/ Zr-βbiphasic alloy. We propose an improved phenomenological model forDHwithrespect to those found in the literature. Furthermore, we study the influence of the Nb content onDHfor the cubic phase Zr-β, employing the transition state theory furnished with ab-initio parameters provided by the SIESTA code. In particular, 9 ordered alloys are considered with different Nb content and effective activation energies are computed by Arrhenius fits for each alloy. We find that activation energies vary in a non-monotonic way as Nb content increases, reaching a maximum value at about Zr-50 %Nb. Finally, we observe that the predicted and measured larger diffusivity along the tube axis vs. the radial direction, is consistent with the material texture. Moreover, we conclude that the loss of continuity of the Zr-βsheets present in the tube microstructure, is consistent with the decrease ofDHin time at a given temperature. |
| first_indexed | 2024-03-12T13:56:15Z |
| format | Article |
| id | doaj.art-cd6607a8610b4b68afe1f4ffd8ffeeef |
| institution | Directory Open Access Journal |
| issn | 0327-358X 1850-1168 |
| language | Spanish |
| last_indexed | 2024-03-12T13:56:15Z |
| publishDate | 2022-01-01 |
| publisher | CEILAP-UNIDEF-CONICET-CITEDEF |
| record_format | Article |
| series | Anales (Asociación Física Argentina) |
| spelling | doaj.art-cd6607a8610b4b68afe1f4ffd8ffeeef2023-08-22T16:02:53ZspaCEILAP-UNIDEF-CONICET-CITEDEFAnales (Asociación Física Argentina)0327-358X1850-11682022-01-01324112119https://doi.org/10.31527/analesafa.2021.32.4.112THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYSG. Beltramo0V. P. Ramunni1R. C. Pasianot2Instituto Sabato, UNSAM/CNEAAv. Gral. Paz 1499, (1650) San Martín, Argentina.2Consejo Nacional de Investigaciones Científicas y Técnicas - CONICETGodoy Cruz 2390 (C1425FQD), Argentina. 3Gcia. Materiales, Comisión Nacional de Energía Atómica,Av. Gral. Paz 1499, (1650) San Martín, Argentina.1Instituto Sabato, UNSAM/CNEAAv. Gral. Paz 1499, (1650) San Martín, Argentina. 2Consejo Nacional de Investigaciones Científicas y Técnicas - CONICETGodoy Cruz 2390 (C1425FQD), Argentina. 3Gcia. Materiales, Comisión Nacional de Energía Atómica,Av. Gral. Paz 1499, (1650) San Martín, Argentina.Within the framework of the delayed hydride cracking phenomena reported for the pressure tubes of CANDU-typenuclear reactors, we study the influence of the Zr-β(∼20 %Nb -∼80 %Zr) continuous phase on the hydrogen diffusion coefficient,DH, through the Zr-α/ Zr-βbiphasic alloy. We propose an improved phenomenological model forDHwithrespect to those found in the literature. Furthermore, we study the influence of the Nb content onDHfor the cubic phase Zr-β, employing the transition state theory furnished with ab-initio parameters provided by the SIESTA code. In particular, 9 ordered alloys are considered with different Nb content and effective activation energies are computed by Arrhenius fits for each alloy. We find that activation energies vary in a non-monotonic way as Nb content increases, reaching a maximum value at about Zr-50 %Nb. Finally, we observe that the predicted and measured larger diffusivity along the tube axis vs. the radial direction, is consistent with the material texture. Moreover, we conclude that the loss of continuity of the Zr-βsheets present in the tube microstructure, is consistent with the decrease ofDHin time at a given temperature.https://anales.fisica.org.ar/index.php/analesafa/article/view/2304/2733zr-nbh diffusionab-initiodelayed hydride cracking |
| spellingShingle | G. Beltramo V. P. Ramunni R. C. Pasianot THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS Anales (Asociación Física Argentina) zr-nb h diffusion ab-initio delayed hydride cracking |
| title | THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS |
| title_full | THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS |
| title_fullStr | THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS |
| title_full_unstemmed | THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS |
| title_short | THEORETICAL AND NUMERICAL STUDY OF HYDROGEN DIFFUSION IN Zr-NbALLOYS |
| title_sort | theoretical and numerical study of hydrogen diffusion in zr nballoys |
| topic | zr-nb h diffusion ab-initio delayed hydride cracking |
| url | https://anales.fisica.org.ar/index.php/analesafa/article/view/2304/2733 |
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