Materials problems related to large-scale combustion of biomass

The project studied oxidation behaviour of TP 347H and X20 in steam in field/laboratory testing and thermodynamic/kinetic modelling. TP 347H: The interior of the alloy grains oxidise internally forming particles of Fe-Cr spinel and Ni/Fe. Ni/Fe forms a network, enabling fast transport of oxygen. FeCr2O4/Cr2O3 forms along the former alloy grain boundaries. Growth of this layer dominates between 7720-29588 h. Higher temperatures enhance Cr-diffusion towards the oxidation front, as confirmed by 2D diffusion modelling. This explaining why the overall growth seems independent of time and temperature. X2O: The inner layer grows by internal oxidation at 500 and 600°C, first converting M23C6 then forming Fe-Cr spinel in between these particles. Alternating layers of Cr-rich and Cr-poor oxide forms at 700 degrees C. (Energy 10)