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

and modeling studies of the oxygen ingression at the crevices of stainless steels were conducted in high-temperature water (288°C). The limiting distance of oxygen ingression, d lim , was defined as the point beyond which the primary surface oxide changed (γ-Fe 2 O 3 –Fe 3 O 4 ), regardless of crevice gap, oxygen concentration, and time. In situ measurements revealed increased electrical conductivity around the d lim position indicating ion enrichment due to a differential oxygen concentration cell. d lim 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. ● The limiting distance of oxygen ingression into the crevice, d lim , was determined. ● An increase in electrical conductivity around the d lim position was revealed. ● d lim increased with the increasing crevice gap, oxygen concentration, and time. ● A modeling study suggested the mechanism that allowed oxygen ingression over time.