Experimental and modeling studies on the oxygen ingression behavior at the crevices of stainless steels in high-temperature water

Soma, Yasutaka   ; Komatsu, Atsushi ; Kaji, Yoshiyuki ; Yamamoto, Masahiro*; Igarashi, Takahiro  

Experimental and modeling studies of the oxygen ingression at the crevices of stainless steels were conducted in high-temperature water (288C). The limiting distance of oxygen ingression, , was defined as the point beyond which the primary surface oxide changed (hematite magnetite), regardless of crevice gap, oxygen concentration, and time. In situ measurements revealed increased electrical conductivity around the position indicating ion enrichment due to a differential oxygen concentration cell. increased with increasing crevice gap, oxygen concentration, and immersion time. Modeling study suggested that oxide layer growth reduced anodic dissolution and slowed oxygen consumption, allowing oxygen ingression with time.