Removal of sea salt from specimen surface using a cavitating jet in air

服部 修次*; Zhang, S.*; 矢田 浩基; 月森 和之

Proceedings of International Symposium on Advanced Mechanical and Power Engineering 2008 (ISAMPE 2008), p.32 - 39, 2008/10

Stress corrosion cracking (SCC) is the unexpected sudden failure of normally ductile metals subjected to a tensile stress in a corrosive environment, especially at elevated temperature. One important form of SCC that concerns the nuclear industry is chloride SCC induced by the existence of sea salt, since most power plants are built at the seaside. Austenitic stainless steels are highly susceptible to chloride SCC, which is the reason why it is necessary to discuss the method to remove sea salt from specimen surface. In this study, a cavitating jet in air, by injecting a high-speed water jet into a concentric low-speed water jet that surrounds the high-speed water jet and is issued into air, was realized for removing the chloride that is one of critical environmental contributors to chloride SCC, especially at stagnant areas and crevices where chloride might become concentrated. Besides, in order to make clear the removal effect of the cavitating jet, the effects of parameters, such as injection pressure of high- and low-speed water jet, stand-off distance, were discussed to acquire an optimum cleaning condition.