Patent ID: 7785425
Filing Date: 2010-08-31
Classification: C23C,H01M,Y02E

Abstract:
1. A stainless steel member passivation treatment method for forming a passive film on a surface of the stainless steel member, said method comprising the steps of: providing an alkaline solution having a pH of 9 to 12, said alkaline solution comprising a pH buffer; immersing the stainless steel member in the alkaline solution at 40 to 60° C. while air is being blown into the alkaline solution to form air bubbles that increase the amount of oxygen dissolved in the alkaline solution and thereby promote the formation of hydroxides constituting the passive film, wherein the hydroxides constituting the passive film are produced from metal ions constituting the stainless steel and hydroxide ions in the alkaline solution, and wherein the pH buffer suppresses a reduction in the pH of the alkaline solution that would otherwise be caused by the dissolution of carbon dioxide into the alkaline solution by the air bubbles; and after the immersing step, thermally drying the member at 100 to 200° C.