Degradation of steel containers by molten Al-12.5 wt.%Si corrosion in a Thermal Energy Storage system

Kurzfassung

Aluminum alloys are of relevance for their use as thermal storage materials in applications that require high energy densities and fast loading and unloading. However, the high-temperature corrosion of molten metals presents a design challenge for the containers of metallic Phase Change Materials (mPCMs). A compromise can be reached by selecting container materials that react with the molten mPCM only to an extent that does not hinder its performance during the product lifetime. The compatibility of Al-12.5wt.%Si used as mPCM and different grades of stainless steel as container has been assessed, including the quantification of the corrosion damage over time and the variation of the storage capacity.