Various tests were conducted to reveal the relationship between the output behaviors of the Atmospheric Corrosion Monitor （ACM） sensor and the amount of corrosion from condensation that occurs as a physical phenomenon. As the sensor output at the time of condensation differs from the behavior when it is wet due to rain or water absorption of adhered sea salt, it was necessary to separately evaluate the behavior. As a result, in the respective phenomena, a relationship was confirmed between the sensor output and the amount of corrosion obtained by measurement in situ. Therefore, this may enable prediction of corrosion speed in a short period using the output of the ACM sensor.

Application of the high strength steel sheet to complicated forming parts has been studied as the weight of automobiles is reduced. Complex strain after forming may affect delayed fracture. Therefore, in this research, we devised a new delayed fracture evaluation method using a forming prediction technology, a forming limit diagram. Forming limit diagram was prepared and stress and hydrogen were applied to each forming mode （single axis, plane strain, biaxial strain）, and crack generation was evaluated. From the results of this study, it was found that the delayed fracture can be evaluated by the method using the forming limit diagram.

A new liquid-phase ion gun （LPIG） technique was developed for safe generation of sulfide ions on metal surfaces in solution, though the LPIG was originally a local chloride ion-generating system used to investigate localized corrosion on metal surfaces as an application of scanning electrochemical microscopy. A silver/silver sulfide microelectrode was used as a liquid-phase sulfide ion gun （LPSIG） instead of a silver/silver chloride microelectrode of an LPIG. Cathodic polarization of the LPSIG microelectrode resulted in the generation of hydrogen sulfide ions in the vicinity of the microelectrode and provided a safe electrochemical environment containing hydrogen sulfide ions. The generation of hydrogen sulfide ions from the LPSIG and the degradation behavior of surfaces of a silver or a type-316L stainless steel are mainly reviewed here. The potential of the LPSIG technique for investigation of hydrogen sulfide-induced corrosion is also discussed.