Abstract
The water of 648K and 22.1MPa or more is called super critical water, and it has characteristics making it an excellent organic solvent. Super critical water, when used in a plastic recycling process, was found to be a very promising environmental benign process technology. Therefore, we have examined its practical use. However, there is a corrosion of metal in supercritical water environments. Therefore, the corrosion of the reactive container is a problem in practical use. The use of economical Fe base alloy is was also examined. However, resistance to corrosion is different according to the use environment and alloy composition. Therefore, to use Fe base alloy for a reactive container, the material to be used must be selected and constructed with the influence of the alloy element on corrosion in relation to a super critical water environment. In Fe-Ni-Cr alloys, the Cr content increased up to 15 mass% in mass, which was composed of Cr_2O_3 on the surface and which also admitted a high corrosion resistance. Especially, the influence of the Cr content became large in permittivity, increasing up to 10. Fe base alloys pitting was mitigated corrosion by adding Mo.
