[3E09-12] Corrosion Potential, Zinc Injection

[3E11] Oxygen Concentration Dependence of the Electrochemical Corrosion Potential of Nickel-Base Alloy 82

*Hikari Murotani¹, Yoichi Wada¹, Ryosuke Shimizu² (1. Hitachi, 2. HGNE)

Keywords:Electrochemical Corrosion Potential, Nickel-Base Alloy, Alloy 82, Electrochemical Corrosion Potential Model, Stress Corrosion Cracking, Boiling Water Reactor

Stress corrosion cracking (SCC) is caused by the superposition of three factors: material, stress, and environment. Electrochemical corrosion potential (ECP) is widely used as an indicator of the environmental factor, and SCC growth rate can be reduced by reducing ECP. Nickel-base alloy weld metal 82 (Alloy 82) used in boiling water reactors (BWR) has superior SCC resistance in terms of the material factor; however, there has been a lack of data on ECPs of Alloy 82. In this study, ECP of Alloy 82 without oxide film in pure water at 280℃, simulating the BWR environment, was measured as a function of oxygen concentration. Compared to 304 stainless steels, Alloy 82 has higher ECPs over a wide range of oxygen concentrations.