High-Temperature Corrosion of HVAF-Sprayed Ni-Based Coatings for Boiler Applications
Journal article, 2019

© 2019, The Author(s). The present study investigates the initial corrosion behaviour of HVAF-sprayed NiCr, NiAl and NiCrAlY coatings in two different environments, O 2 + H 2 O and O 2 + H 2 O + KCl at 600 °C for up to 168 h in order to evaluate the possibility of utilizing such coatings in biomass- and waste-fired boilers. SEM/EDX analysis showed that all coatings displayed a protective behaviour in O 2 + H 2 O. Upon addition of KCl (O 2 + H 2 O + KCl), the corrosion behaviour of the NiCr coating drastically changed as it formed a thick oxide layer and displayed major chlorine diffusion down to the substrate. The NiCrAlY coating displayed a significantly better corrosion resistance with only minor oxide formation. The NiAl coating exhibited a protective behaviour similar to when exposed in the absence of KCl indicating that a thin protective oxide has formed on the coating surface. The performance of the NiAl and NiCrAlY coatings is promising for future studies with long-term exposures in more corrosive environments such as in a biomass- and waste-fired boiler.

HVAF

Ni-based coatings

Waste

KCl-induced corrosion

Biomass

Author

Johan Eklund

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Julien Phother Simon

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

E. Sadeghi

University West

S. Joshi

University West

Jesper Liske

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Oxidation of Metals

0030-770X (ISSN) 1573-4889 (eISSN)

Subject Categories

Manufacturing, Surface and Joining Technology

Medical Materials

Corrosion Engineering

DOI

10.1007/s11085-019-09906-0

More information

Latest update

10/28/2019