2019 №09 (03)

DOI of Article 10.15407/as2019.09.04

2019 №09 (05)

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Avtomaticheskaya Svarka (Automatic Welding), #9, 2019, pp. 31-39

Heat-resistant thermal coatings based on FeAlCr intermetallics with CeO₂ additives

Yu.S. Borisov¹, A.L. Borisova¹, T.V. Tsymbalista¹, N.I. Kaporik¹, M.A. Vasilkovskaya²

¹E.O. Paton Electric Welding Institute of the NAS of Ukraine, 11 Kazimir Malevich Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
²Frantsevich Institute for Problems of Material Science, 3 Krzhizhanovskogo Str, 03680, Kyiv, Ukraine. E-mail: kiparis-gpk@ukr.net

The paper presents the results of studying the heat resistance of coatings, produced by the methods of plasma (PS) and high-speed flame spraying (HSFS), using composite powder based on FeAlCr with addition of 2 wt.% CeO₂, as well as by the methods of arc spraying (AS) and activated arc spraying (AAS) with application of flux-cored wire of the following composition 98(82Fe+16Al+2Cr)+2CeO₂ (wt.%). Composite powder was prepared by the method of mechanico-chemical synthesis (MChS) by treating a mixture of powder components in a planetary-type mill. Heat-resistance testing was performed in air at 800, 900 and 1000 °C for 7 hours by weight method. Coating structure after heat-resistance testing was studied with application of metallographic and X-ray structural analysis (RSPhA). It is found that during testing of coatings produced by PS and HSFS methods the delamination phenomenon is observed, whereas coatings produced by AS and AAS methods preserve a tight bond with the base. Obtained kinetic curves of high-temperature resistance showed that in the entire time interval of testing at 800 – 1000 °C the oxidation mechanism follows the parabolic law. The data of kinetic dependencies were used to plot the parametric heat resistance diagrams, allowing evaluation of fatigue life of the studied protective coatings in the temperature range of 800 – 1000 °C. The highest heat resistance is found in FeAlCrCeO₂ coatings produced by AS and AAS methods from flux-cored wire. At 1000 °C it exceeds the resistance of steel 45 23-26 times, and corresponds to heat resistance of 08Kh17T steel. 12 Ref., 2 Tabl., 8 Fig.
Keywords: flame spraying, arc spraying, iron-aluminium intermetallics, mechanico-chemical synthesis, composite powder, flux-cored wire, parametric heat-resistance diagram, FeAlCr-CeO₂ system

Received: 12.06.2019

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