High-Temperature Corrosion Behavior of Selected HVOF-Sprayed Super-Alloy Based Coatings in Aggressive Environment at 800°C

0574773 - ÚFP 2024 RIV CH eng J - Journal Article
Česánek, Z. - Lencová, K. - Schubert, J. - Antoš, J. - Mušálek, Radek - Lukáč, František - Palán, M. - Vostřák, M. - Houdková, Š.
High-Temperature Corrosion Behavior of Selected HVOF-Sprayed Super-Alloy Based Coatings in Aggressive Environment at 800°C.
Materials. Roč. 16, č. 12 (2023), č. článku 4492. E-ISSN 1996-1944
Institutional support: RVO:61389021
Keywords : hot corrosion * molten salt * hvof * Ni-based coatings * Co-based * gravimetric method * Na2SO4 * NaCl * MCrAlYX
OECD category: Materials engineering
Impact factor: 3.4, year: 2022
Method of publishing: Open access
https://www.mdpi.com/1996-1944/16/12/4492

This study is focused on the high-temperature corrosion evaluation of selected thermally sprayed coatings. NiCoCrAlYHfSi, NiCoCrAlY, NiCoCrAlTaReY, and CoCrAlYTaCSi coatings were sprayed on the base material 1.4923. This material is used as a cost-efficient construction material for components of power equipment. All evaluated coatings were sprayed using HP/HVOF (High-Pressure/High-Velocity Oxygen Fuel) technology. High-temperature corrosion testing was performed in a molten salt environment typical for coal-fired boilers. All coatings were exposed to the environment of 75% Na2SO4 and 25% NaCl at the temperature of 800°C under cyclic conditions. Each cycle consisted of 1 h heating in a silicon carbide tube furnace followed by 20 min of cooling. The weight change measurement was performed after each cycle to establish the corrosion kinetics. Optical microscopy (OM), scanning electron microscopy (SEM), and elemental analysis (EDS) were used to analyze the corrosion mechanism. The CoCrAlYTaCSi coating showed the best corrosion resistance of all the evaluated coatings, followed by NiCoCrAlTaReY and NiCoCrAlY. All the evaluated coatings performed better in this environment than the reference P91 and H800 steels.
Permanent Link: https://hdl.handle.net/11104/0351323