CORROSION RESISTANCE OF SELECTED HVOF THERMALLY SPRAYED COATINGS

1 ČESÁNEK Zdeněk
Co-authors:
1 SCHUBERT Jan 1 HOUDKOVÁ Šárka
Institution:
1 VZÚ Plzeň - Výzkumný a zkušební ústav Plzeň, Plzeň, Czech Republic, EU
Conference:
25th Anniversary International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 25th - 27th 2016
Proceedings:
Proceedings 25th Anniversary International Conference on Metallurgy and Materials
Pages:
1031-1036
ISBN:
978-80-87294-67-3
ISSN:
2694-9296
Published:
14th December 2016
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
87 views / 33 downloads
Abstract

Corrosion resistance of coatings deposited using the HP/HVOF (High Pressure/High Velocity Oxygen Fuel) thermal spraying technology requires high coatings density and a good adhesion to the substrate. The majority of thermally sprayed materials meet the requirements for high corrosion resistance in terms of their composition. However, the porous structure raises doubts about the performance of thermally sprayed coatings in providing sufficient protection to the base material. In fact, corrosion protection is one of the basic coating functions. Anyway, in comparison with wear resistance research, an insufficient attention is paid to the issue of component protection against corrosion attack using the HVOF sprayed coatings. This paper summarizes the results of immersion corrosion tests performed on six selected corrosion resistant coatings, which are compared with the Wr.Nr. 1.4923 nitrided stainless steel. The following coatings were tested: two based cermet coatings (Cr3C2-NiCr, Cr3C2-CoNiCrAlY), three alloy based coatings (CoCrWC - Stellite 6, NiCrBSi, and NiCrMo - Hastelloy C-276) and one experimental coating (TiMoCN-29%Ni). These coatings were selected as good candidates for the use in corrosive aggressive environments. Steel Wr.Nr. 1.0421 was used as the base material. Corrosion experiment was performed in 5% solution of H2SO4 (further H2SO4). The evaluation of corrosion attack was made before and after corrosion tests on surface and in coating cross-section after metallographic grinding using an optical microscope (OM).

Keywords: HP/HVOF, corrosion resistance, immersion corrosion test, coating

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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