Determination of mass transfer coefficient in flow assisted corrosion of steel in liquid Pb Bi. Rotating cylinder geometry

The aim of this experimental and numerical work is to determine the mass transfer at the wall of a steel cylinder rotating within liquid Lead-Bismuth blend. This is a crucial parameter for the analysis of corrosion tests performed in the CICLAD experimental set-up for the investigation of flow assisted corrosion of steel by liquid metals. As a reliable numerical modelling must rely on experimental validation, and since no direct wall mass transfer measurement is possible in CICLAD, a scaled electrochemical model has been achieved. Modelling the turbulence in this rotating configuration is shown to require the use of a Reynolds-Stress Model. A sensitivity to the Schmidt number is observed in the numerical simulations representing the measured mass transfer in the electrochemical model. Simulations dedicated to liquid PbBi are thus presented in addition to those dedicated to the aqueous solution used in the electrochemical model. Following correlations are proposed for the prediction of Fe mass transfer at the wall of a steel rotating cylinder in liquid Pb-Bi:Sh = 1.9 × 10−1(Re2Sc)0.31 for 2 × 109 < Re2Sc < 5.3 × 1010;Sh = 1.4 × 10−3(Re2Sc)0.51 for 5.3 × 1010 < Re2Sc < 8.5 × 1011;Sh = 1.1 × 10−2(Re2Sc)0.43 for 8.5 × 1011 < Re2Sc < 1013.This mass transfer coefficient has recently been used to get a better understanding of corrosion in PbBi [1].