Uniform corrosion behavior of FeCrAl alloys in borated and lithiated high temperature water.

• Research highlights of the present work are listed as follows: • FeCrAl alloys exhibited better corrosion resistance than commercial Zircaloy-4. • Oxide film consists of outer Fe 3 O 4 layer, inner spinel layer and transition layer. • Compact spinel layer in inner layer can block inward diffusion of oxygen. • Porous spinel layer in inner layer was caused by outward diffusion of Fe²⁺. • The small addition of yttrium had no effect on corrosion of FeCrAl alloys. The uniform corrosion behavior of model FeCrAl alloys as well as commercial Zircaloy-4 as reference material were investigated in 360 °C borated and lithiated water. The results reveal that FeCrAl alloys exhibited better corrosion resistance than Zircaloy-4. It is found that the oxide films formed on the FeCrAl alloys are composed of outer Fe 3 O 4 layer, inner layer consisting of compact spinel layer and porous spinel layer, and transition layer containing Al-Cr-rich oxides and matrix enriched with Fe°. The spinel oxides in the inner layer are FeFe 2- x - y -z Cr x Al y Mo z O 4. The corrosion mechanism of FeCrAl alloys in high temperature water is discussed. [ABSTRACT FROM AUTHOR]