TY - JOUR
T1 - Effects of thermo-mechanical process on phase transitions, hydrogen solubility and corrosion of Ta-modified Zr-1Nb alloys
AU - Ferreirós, P.A.
AU - Savoy Polack, E.C.
AU - Lanzani, L.A.
AU - Alonso, P.R.
AU - Quirós, D.P.
AU - Mieza, J.I.
AU - Rubiolo, G.H.
PY - 2021/5/5
Y1 - 2021/5/5
N2 - 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 훽푍푟: a) annealed at 570 °C for 3840 h and b) a combination of intermediate annealing temperatures and cold rolled steps. Hydrogen solubility was also measured, but only 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 훼 → (훼 + 훽) phase transformation temperature in agreement with an estimated increase in the enthalpy of formation of the 훽푁푏⁄푇푎 phase, ∆퐻푓훽푁푏⁄푇푎. As expected, the mass fraction of 훽푁푏⁄푇푎 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 ∆퐻푓훽푁푏⁄푇푎. The growth of the oxide layer in each alloy, at 400 °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 ∆퐻푓훽푁푏⁄푇푎. A slight decrease in hydrogen solubility was observed at low Ta content in the alloy.
AB - 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 훽푍푟: a) annealed at 570 °C for 3840 h and b) a combination of intermediate annealing temperatures and cold rolled steps. Hydrogen solubility was also measured, but only 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 훼 → (훼 + 훽) phase transformation temperature in agreement with an estimated increase in the enthalpy of formation of the 훽푁푏⁄푇푎 phase, ∆퐻푓훽푁푏⁄푇푎. As expected, the mass fraction of 훽푁푏⁄푇푎 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 ∆퐻푓훽푁푏⁄푇푎. The growth of the oxide layer in each alloy, at 400 °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 ∆퐻푓훽푁푏⁄푇푎. A slight decrease in hydrogen solubility was observed at low Ta content in the alloy.
KW - Ta addition
KW - Zr–Nb alloy
KW - corrosion
KW - hydrogen solubility
KW - phase transformation
UR - http://www.scopus.com/inward/record.url?scp=85107077485&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2021.153039
DO - 10.1016/j.jnucmat.2021.153039
M3 - Article
SN - 0022-3115
VL - 553
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 153039
ER -