Strain rate susceptibility of stress corrosion cracking for commercial Zr702 used in spent nuclear fuel reprocessing

ABSTRACT

Slow strain rate tensile (SSRT) experiments were applied to comprehensively examine the strain rate susceptibility of the stress corrosion cracking behaviour of commercial Zr702 used in the spent nuclear fuel reprocessing environment. Results revealed that layers formed on Zr702 in boiling HNO₃ solutions was composed of monoclinic ZrO₂ (m-ZrO₂) and tetragonal ZrO₂ (t-ZrO₂). With strain rates above 10⁻⁴ s⁻¹, oxide layers ruptured rapidly, evidenced by the drop down of opened circuit potential (OCP). However, the OCP curve displayed fluctuation with 10⁻⁵ s⁻¹ during straining, indicating that oxide layer alternately ruptured and repaired, resulting in the thickening of the oxide layer and increasement of stress corrosion cracking susceptibility.

KEYWORDS:

• Zr702
• SSRT
• stress corrosion cracking
• electrochemical
• strain rate sensitivity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Xi’an Science and Technology Plan Project: [Grant Number 2020YZ0028]; the RMMI research project: [Grant Number Y1905S]; the Innovation Center of Nuclear Materials for National Defense Industry: [Grant Number ICNM- 2021-ZH-16]; the Qinchuangyuan Project of Shaanxi Province: [Grant Number 2021QCY1-01].