Corrosion performance of alloy 800H and alloy 625 for potential use as molten salts solar receiver materials in concentrating solar power tower plants

Two high corrosion resistant super-alloys, alloy 800H and 625, were evaluated for compatibility with molten nitrate salts at 565 °C under air atmosphere since these super-alloys are possible candidates the manufacturing of solar receivers in CSP tower technology. Both alloys tested two different grades to identify how impurities final mixture affect damage. Accordingly, a technical grade salt (Solar_Salt_T) refined (Solar_Salt_R) selected as test media. In addition rates calculation, techniques such XRD, EDS, optical scanning electron microscopy used morphology oxides layers chemistry. Alloy 625 show uniform after testing without detecting localized phenomena pitting, stress cracking, crevice, or intergranular corrosion. While develops duplex oxide layer consisting iron its external part, chromium innermost layer, generates compact highly adherent mainly nickel oxide. Corrosion decrease time, being higher exposed Solar_Salt_T mixtures. Moreover, shows lower than all conditions this study. • Tested testing. layer.