Evaluation of flow accelerated corrosion and mechanical performance of martensitic steel T91 for a ternary mixture of molten salts for CSP plants

Thermal energy storage (TES) systems with molten salts involve different operating conditions causing corrosion problems in the materials due to the high operating temperature. In this work, the corrosion behavior was studied by means of flow accelerated corrosion (FAC) and static corrosion tests in contact with the ternary mixture (KLiNa)NO3 at 550 °C. Both tests were performed by gravimetric tests (mass gain) and subsequently characterized by SEM and XRD. The results showed a substantial increase in mass gain due to the dynamic effect of the FAC test in relation to the stationary test.