METHOD FOR DECREASING STRESS CORROSION CRACKING SENSITIVENESS IN SUPERCRITICAL OR SUBCRITICAL WATER

摘要

PPROBLEM TO BE SOLVED: To provide a method for decreasing the stress corrosion cracking sensitiveness of a material of a reaction vessel, by which the stress corrosion cracking sensitiveness can be decreased and the corrosion rate of the whole inside surface of the reaction vessel can be restrained from being accelerated. PSOLUTION: This method for decreasing the stress corrosion cracking sensitiveness of the material of the reaction vessel is used when organic matter is treated in the water kept in a supercritical or subcritical state in a metal-made reaction apparatus. The method comprises a step of injecting formic acid into the water kept in the supercritical or subcritical state or into the reaction apparatus. In the concrete, when the reaction apparatus is made from stainless steel, the molar ratio of the formic acid to be injected to the water kept in the supercritical or subcritical state is 0.02-0.5 and when the reaction apparatus is made from a Ni-based alloy, that of the formic acid to the water kept in the supercritical or subcritical state is 0.002-0.5. PCOPYRIGHT: (C)2006,JPO&NCIPI