METHOD FOR FORMING OXIDATION-PASSIVE LAYER, FLUID-CONTACTING PART, AND FLUID FEED/DISCHARGE SYSTEM

摘要

A method for forming an oxidation-passive layer having high corrosion resistance to highly oxidizing materials such as ozone; a stainless steel and a titanium-base alloy having high corrosion resistance to an ozone-containing fluid; and a fluid-contacting part, a process apparatus, and a fluid feed/discharge system made by using the same. The method is characterized by heat-treating the surface of a stainless steel or titanium-base alloy having an Al content of 0.5 to 7 % by weight either at 300 to 700 DEG C in a mixed gas atmosphere composed of an inert gas and 500 ppb to 1 % H2O gas or 1 to 500 ppm oxygen gas, or alternatively at 20 to 300 DEG C in a mixed gas atmosphere composed of an oxygen gas and at least 100 ppm ozone gas to form an oxidation-passive layer containing an aluminum oxide or a titanium oxide.