Measurement of the Nickel/Nickel Oxide Phase Transition in High Temperature Hydrogenated Water Using the Contact Electric Resistance (CER) Technique.

Attanasio, S. A. ; Morton, D. S. ; Ando, M. A. ; Panayotou, N. F. ; Thompson, C. D.

Technical Information Center Oak Ridge Tennessee

关键词: Nickel alloys;    Hydrogen;    Chemistry;    Oxides;    Electric conductivity;   

RP-ID  :  DE2004821680

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Prior studies of Alloy 600 and Alloy X-750 have shown the existence of a maximum in stress corrosion cracking (SCC) susceptibility in high temperature water (e.g., at 360 degrees C), when testing is conducted over a range of dissolved (i.e., aqueous) hydrogen (H(sub 2)) concentrations. It has also been shown that this maximum in SCC susceptibility tends to occur in proximity to the nickel/nickel oxide (Ni/NiO) phase transition, suggesting that oxide phase stability may affect primary water SCC (PWSCC) resistance. Previous studies have estimated the Ni/NiO transition using thermodynamic calculations based on free energies of formation for NiO and H(sub 2)O. The present study reports experimental measurements of the Ni/NiO transition performed using a contact electric resistance (CER) instrument.