Corrosion Behaviour of Plasma-Sprayed Nickel Coating on Type 316L Stainless Steel in High-Temperature Molten FLiNaK Salt

Autor: S. Rangarajan, T.V. Krishna Mohan, S. Ningshen, Ch. Jagadeeswara Rao, Shaju K. Albert, Y. V. Harinath
Rok vydání: 2021
Předmět:
Zdroj: Transactions of the Indian Institute of Metals. 74:2821-2833
ISSN: 0975-1645
0972-2815
Popis: Molten fluoride salts are proposed as coolant in nuclear and solar power plants. It is essential to study material compatibility of various candidate structural materials and coatings for molten salt applications. In this work, corrosion behaviour of plasma-sprayed Ni coating on SS316L at 650 °C for 1000 h has been evaluated. Argon gas shrouded plasma-sprayed Ni coating did not show any formation of nickel oxides during the coating process. There was no coating loss or delamination of the coating from the substrate even after exposure for 1000 h at 650 °C. However, separation of coating from substrate at the interface was observed, which could be attributed to mismatch in thermal expansion of the substrate and Ni coating. Surface morphology examination of the coated specimens after molten salt exposure showed no penetration of salt into the coating. The XRD and LRS results indicated that there was no new compound or phase formed and from this it can be inferred that the Ni coating did not react with the molten FLiNaK salt during exposure. However, the Ni coating reacted with the oxygen present in the argon cover gas as impurity to form nickel oxide at high temperature.
Databáze: OpenAIRE
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