Crack initiation behavior of stress corrosion cracking on zirconium in boiling nitric acid solution

Ishijima, Yasuhiro ; Kato, Chiaki   ; Yamamoto, Masahiro 

Zirconium has been utilized in chemical plant because of its superior corrosion resistance. But stress corrosion cracking (SCC) susceptibility and black oxide film growth had been reported under elastic stress condition. In order to clarify the SCC crack initiation and growth behavior of Zr in boiling nitric acid solution, constant load tests at potentiostatic condition were conducted. From the results, SCC crack generated from the oxide/metal interface into metal. This result suggests that the oxide generation induces tensile stress at the oxide/metal interface. And it is considered the stress acts as SCC crack generator.