Advances in Corrosion-Resistant Thermal Spray Coatings for Renewable Energy Power Plants. Part I: Effect of Composition and Microstructure

Abstract

Power generation from renewable resources has attracted increasing attention in recent years owing to the global implementation of clean energy policies. However, such power plants suffer from severe high-temperature corrosion of critical components such as water walls and superheater tubes. The corrosion is mainly triggered by aggressive gases like HCl, H 2 O, etc., often in combination with alkali and metal chlorides that are produced during fuel combustion. Employment of a dense defect-free adherent coating through thermal spray techniques is a promising approach to improving the performances of components as well as their lifetimes and, thus, significantly increasing the thermal/electrical efficiency of power plants. Notwithstanding the already widespread deployment of thermal spray coatings, a few intrinsic limitations, including the presence of pores and relatively weak intersplat bonding that lead to increased corrosion susceptibility, have restricted the benefits that can be derived from these coatings. Nonetheless, the field of thermal spraying has been continuously evolving, and concomitant advances have led to progressive improvements in coating quality; hence, a periodic critical assessment of our understanding of the efficacy of coatings in mitigating corrosion damage can be highly educative. The present paper seeks to comprehensively document the current state of the art, elaborating on the recent progress in thermal spray coatings for high-temperature corrosion applications, including the alloying effects, and the role of microstructural characteristics for understanding the behavior of corrosion-resistant coatings. In particular, this review comprises a substantive discussion on high-temperature corrosion mechanisms, novel coating compositions, and a succinct comparison of the corrosion-resistant coatings produced by diverse thermal spray techniques.

Recent Development of Corrosion Factors and Coating Applications in Biomass Firing Plants

“…The biomass components include cellulose, hemicellulose, lignin, water, small amounts of lipids, proteins, monosaccharides, starches, hydrocarbons, ash, and other ingredients. These components produce chlorides, sulfates, polysulfates, and sulfides after combustion, leading to the corrosion of metals and metal oxides in the boiler [20]. Vassilev et al [11] reported that kinds of biomass have similar composition and a little difference between the mass.…”

Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films

“…The deposition method of anti-corrosive coatings is a crucial factor in determining the surface morphology. Coatings are usually produced by spin casting [38][39][40], molecularlayer deposition (MLD) [41,42], vapor-deposition polymerization (VDP) [43,44], or spray coating techniques [45,46]. These methods adopt a layer-by-layer deposition approach, and each layer adheres to each other rapidly, hindering the crosslinking of polymer chains and resulting in cracks and low strength [47][48][49][50].…”

Influence of Non-Metallic Inclusions on the Corrosion Resistance of Stainless Steels in Arc Surfacing

“…Surfacing with hard wear-resistant materials [Kartsev 2020] is intended to increase the wear resistance of sealing, rubbing, and other surfaces of parts operating under conditions of metal-to-metal friction in corrosive media (acid, alkali, salt, and organic solvent) [Panda 2014[Panda , 2018a[Panda ,b, 2019Valicek 2016& 2017, Macala 2009& 2017, Pandova 2018, Krenicky 2012, high and low temperatures, and/or pressure [Bozek 2021]. The research [Sadeghi 2019] includes a substantive discussion of high-temperature corrosion mechanisms, new coating formulations, and a brief comparison of corrosion-resistant coatings obtained using various thermal surfacing techniques. It is suggested that with a careful and reasonable choice of technique and technology of surfacing, as well as compliance with a certain temperature range of pre-and associated heating of parts, it will be possible to obtain a high-quality connection of wear-resistant layers of alloys based on iron, nickel or cobalt [Miglierini 2004, Babinets 2020, Pollak 2020a.…”