In recent years, due to growing concerns about environmental and health risks, there has been a movement, particularly in Europe, to tighten regulations on compounds currently used in corrosion inhibitors. To address this challenge, we aimed to develop copper corrosion inhibitors with lower environmental impact. To accelerate the discovery of alternatives, we developed a Materials Informatics （MI） technology based on our company's accumulated knowledge, and constructed an MI model specifically for copper corrosion inhibitors. This MI model was then applied to an external molecular structure database to identify potential candidates with reduced environmental hazards. Our approach successfully highlighted several promising compounds, demonstrating the potential of MI in facilitating sustainable material development.

Sulfidation corrosion rate of Ag in H₂S/NO₂ mixed gas atmosphere was evaluated using resistance measurement method. As a result, the corrosion of Ag was accelerated about 100 times in H₂S/NO₂ mixed gas compared with H₂S single gas. The corrosion behavior changes at the concentration ratio of H₂S : NO₂＝1 : 2, and the corrosion rate shows a negative temperature dependence and no humidity dependence. It was also confirmed that S₈ was detected in the H₂S/NO₂ mixed gas using HPLC （High Performance Liquid Chromatography） method. Based on these results, mechanisms of Ag sulfidation corrosion by H₂S/NO₂ mixed gas atmosphere were proposed.