Properties of oxide films formed on 316L SS and model alloys with modified Ni, Cr and Si contents in high temperature water

Oxide films formed on 316L stainless steel, 9Cr-26Ni-1.5Mo, and 9Cr-26Ni-1.5Mo-5Si in de-aerated high temperature water have been characterized. High reactivity of Si and high solubility of silicon oxides in high temperature water contribute to Si depletion in the outer oxide layer, Si enrichment in the inner oxide layer near the metal/oxide interface, and the outer layer of large and continuously packed oxides with cavities. A higher Cr content in the alloys favors the formation of a thinner inner oxide layer. Si in the model alloy affects the distribution of nickel oxide near the metal/oxide interface.