TY - JOUR
T1 - Role of headspace environment for phase change carbonates on the corrosion of stainless steel 316L
T2 - High temperature thermal storage cycling in concentrated solar power plants
AU - Yin, Yanting
AU - Rumman, Raihan
AU - Sarvghad, Madjid
AU - Bell, Stuart
AU - Ong, Teng-Cheong
AU - Jacob, Rhys
AU - Liu, Ming
AU - Flewell-Smith, Ross
AU - Sheoran, Shane
AU - Severino, John
AU - Belusko, Martin
AU - Bruno, Frank
AU - Will, Geoffrey
AU - Steinberg, Theodore A.
AU - Lewis, David A.
AU - Andersson, Gunther G.
PY - 2023/3
Y1 - 2023/3
N2 - The mechanisms leading to corrosion in stainless steel containments for thermal energy storage through phase change materials, such as carbonates and chlorides, are crucial for understanding the degradation of these steel alloys. A comprehensive study of this area will allow for down-selection of materials suitable for solar thermal energy storage (TES) operation at an elevated temperature range. Samples of stainless steel (SS) 316L were subjected to a cyclic heat environment of 550–750 °C in air and argon headspace environments, in the presence of a carbonate salt phase change material (PCM). A series of complementary microscopy, spectroscopy and diffractometry analytical techniques were applied to the corroded SS316L. Corrosion rate, interface formation and chemical products with respect to thermal cycling are presented with associated degradation mechanism explained and comparisons are made among different gas environments and varied immersion conditions. In the PCM under ambient air conditions, steel surfaces were mainly corroded by the penetration of oxidants from air, such as H2O or O2, along grain boundaries. SS316L samples demonstrated more severe degradation when exposed to air with a small fraction of PCM vapour present compared to when they were exposed to liquid or solid PCM. Cycling in Ar resulted in less corrosion in samples as opposed to when they were exposed to an air environment. In an Ar environment corrosion is driven via the formation of chromite, while the SS316L showed a less degradation when exposed to Ar with a small fraction of PCM vapour compared to when it was immersed in PCM. The mechanisms for degradation in air and in Ar are common in that the corrosion products of Cr and Ni dissolve in the PCM thus removing any layer that could protect against corrosion. The present study provides insight into corrosion of stainless-steel when exposed to carbonate salts, in air and inert gas environments, and contributes to down-selection of materials for solar thermal energy storage.
AB - The mechanisms leading to corrosion in stainless steel containments for thermal energy storage through phase change materials, such as carbonates and chlorides, are crucial for understanding the degradation of these steel alloys. A comprehensive study of this area will allow for down-selection of materials suitable for solar thermal energy storage (TES) operation at an elevated temperature range. Samples of stainless steel (SS) 316L were subjected to a cyclic heat environment of 550–750 °C in air and argon headspace environments, in the presence of a carbonate salt phase change material (PCM). A series of complementary microscopy, spectroscopy and diffractometry analytical techniques were applied to the corroded SS316L. Corrosion rate, interface formation and chemical products with respect to thermal cycling are presented with associated degradation mechanism explained and comparisons are made among different gas environments and varied immersion conditions. In the PCM under ambient air conditions, steel surfaces were mainly corroded by the penetration of oxidants from air, such as H2O or O2, along grain boundaries. SS316L samples demonstrated more severe degradation when exposed to air with a small fraction of PCM vapour present compared to when they were exposed to liquid or solid PCM. Cycling in Ar resulted in less corrosion in samples as opposed to when they were exposed to an air environment. In an Ar environment corrosion is driven via the formation of chromite, while the SS316L showed a less degradation when exposed to Ar with a small fraction of PCM vapour compared to when it was immersed in PCM. The mechanisms for degradation in air and in Ar are common in that the corrosion products of Cr and Ni dissolve in the PCM thus removing any layer that could protect against corrosion. The present study provides insight into corrosion of stainless-steel when exposed to carbonate salts, in air and inert gas environments, and contributes to down-selection of materials for solar thermal energy storage.
KW - Corrosion resistance
KW - High temperature corrosion
KW - Solar energy
UR - http://www.scopus.com/inward/record.url?scp=85145214784&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2022.112170
DO - 10.1016/j.solmat.2022.112170
M3 - Article
AN - SCOPUS:85145214784
SN - 0927-0248
VL - 251
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 112170
ER -