Study on mechanical properties of Inconel 625 and Incoloy 800H with nitrate based molten salts

Abstract

Energy storage is the most indispensable technology in the recent days with augmented power demand, which helps in balancing the energy demand and production time. Among the broad spread of energy storage types, molten salts technology in concentrated solar plants is most economical, highly efficient with excellent duration on the storage timings. In this current effort, Inconel 625 and Incoloy 800H nickel based super alloys have been taken and heated with sodium nitrate and potassium nitrate molten salts. The super alloy substrates were coated with Yttria stabilized zirconia as thermal barrier coating which could enhances the heat resistance and corrosion resistance property of the base substrates. Both layered and non-coated super alloy samples were intense to a fairly accurate temperature of 1000 o C for different duration as 9, 12 and 15 hours. The mechanical properties of both unheated and heated specimens were compared with the results obtained from tensile test, compression test, hardness test, and impact test. The changes in the micro-structural properties were investigated with the support of SEM images and by XRD analysis. The mechanical properties of YSZ coated specimens are found to be better than the uncoated specimens; which increases the sustainability of the super alloys with the molten salts.

Keywords

• inconel 625
• incoloy 800h
• yttria stabilized zirconia
• sodium nitrate
• potassium nitrate salts and hot corrosion