Corrosion of T91 and pure iron in flowing and static Pb-Bi alloy between 450 °C and 540 °C: experiments, modelling and mechanism

T91 (Fe-9Cr steel) and pure iron were corroded in pure dissolution domain in liquid lead bismuth eutectic (LBE) from 450 to 540 degrees C in static and in dynamic LBE flow. The modelling showed that corrosion rates were controlled: (i) for static condition (LBE natural convection), by the iron diffusion in the diffusion boundary layer; (ii) for flowing LBE, by a mixed process combining both the interfacial reaction rate of iron dissolution and the iron diffusion rate in the diffusion boundary layer. By fitting the modelling on the experimental points, the constant of interfacial reaction rate was determined.