Effects of thermo-mechanical process on phase transitions, hydrogen solubility and corrosion of Ta-modified Zr-1Nb alloys

JOURNAL OF NUCLEAR MATERIALS

卷:553

Article

Ferreiros, P. A.^1,2,3  Savoy Polack, E. C.¹  Lanzani, L. A.¹  Alonso, P. R.¹  Quiros, P. D.¹  Mieza, J., I¹  Rubiolo, G. H.^1,2 

[1] Univ Nacl San Martin UNSAM, Inst Sabato, Gerencia Mat GAEN, Comis Nacl Energia Atom CNEA, Av Gral Paz 1499,B1650KNA, San Martin, Buenos Aires, Argentina

[2] Consejo Nacl Invest Cient & Tecn CONICET, Godoy Cruz 2290,C1425FQB, Buenos Aires, DF, Argentina

[3] Univ Birmingham, Sch Met & Mat, Birmingham B15 2TT, W Midlands, England

关键词: Zr-Nb alloy;    Ta addition;    Phase transformation;    Corrosion;    Hydrogen solubility;   

DOI  :  10.1016/j.jnucmat.2021.153039

来源: Elsevier

【 摘 要 】

The feasibility of using Ta as a minor alloying element in Zr-1Nb alloys is addressed in terms of phase stability and resistance to corrosion of the microstructure obtained with the following two thermomechanical processes after a water quenching from beta(Zr): a) annealed at 570 degrees C for 3840 h and b) a combination of intermediate annealing temperatures and cold rolled steps. Hydrogen solubility was also measured, but only in alloys with the first process. It was found, through calorimetric measurements, that an increase of Ta replacing Nb in the nominal alloy composition increases the alpha -> (alpha + beta) phase transformation temperature in agreement with an estimated increase in the enthalpy of formation of the beta(Nb/Ta) phase, Delta H-beta Nb/Ta(f). As expected, the mass fraction of beta(Nb/Ta) measured in the rolled alloys is lower. Further, this diminution is larger in the alloys containing Ta due to the lower mobility of Ta and higher Delta H-beta Nb/Ta(f). The growth of the oxide layer in each alloy, at 400 degrees C steam up to 14 days, follows the predictor calculated as the ratio between the atomic concentrations of Nb plus Ta in the alloy and A(beta Nb/Ta)(f). A slight decrease in hydrogen solubility was observed at low Ta content in the alloy. (C) 2021 Elsevier B.V. All rights reserved.

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