METHOD FOR EVALUATING CORROSION RESISTANCE OF METALLIC MATERIAL, METHOD FOR DESIGNING HIGH CORROSION-RESISTANT ALLOY, METHOD FOR DIAGNOSING CORROSION STATE OF METALLIC MATERIAL AND METHOD FOR OPERATING PLANT

摘要

PURPOSE:To evaluate a corrosion damage, etc., based on a theoretical background by comparing a critical condition determined on the basis of data including a level of a valence band of a passive state film in a flat band state and a Fermi level of a corrosion system. CONSTITUTION:The dissolving speed of a passive state film is exponential function of potential difference DELTAphiH in an electric double layer. Therefore, when the potential difference DELTAphiH in the electric double layer is increased even slightly, the dissolving speed is increased rapidly. That is, a stable area is broken. Therefore, a critical condition determined based on data including a level of a valence electron band of the passive state film in a flat band state is obtained. Moreover, a Fermi level of a corrosion system including the passive state film and a corrosion environment under a target corrosion environment is obtained. A corrosion resistance is evaluated by comparing the Fermi level with the critical condition. Accordingly, environment in a plant (e.g. quality of cooling water in an atomic plant) can be controlled to make a structural material stable.