Water of 648K and 22.1MPa or more is called super critical water, and it has an excellent organic solvent characteristic. Recently, the application of supercritical water in various fields has been tried. However, metal corrodes in supercritical water environments, especially, reactive containers corrode remarkably with hydrochloric acid caused in processing of PCB. Therefore, the corrosion of reactive containers and their longevity are serious problems. It is important to make a long-life reactive container. In this study, the corrosive behavior of nitrided SUS316L was investigated in supercritical water at 523 to 873K and 30 to 35MPa for 2.6×10^5 to 5.22×10^5 sec. Similar test of a surface treated specimen was also carried out. The result was that the corrosion rate increased as the examination temperature increased in all materials.
