A review of thermal spray coatings for protection of steels from degradation in coal fired power plants

Abstract

In coal fired power plants, the metallic surfaces such as boiler tubes, walls of combustion chambers and other parts degrade by corrosion, erosion and abrasion. It happens due to the hot gaseous environment, steam oxidation and presence of hard minerals and impurities in the coal. It is very important to protect these surfaces from material loss, otherwise it would lead to increased repair and maintenance cost along with decreased plant efficiency. In this paper, the role of thermal spray coatings has been studied for the protection of different steel grades exposed to such degrading conditions at high temperatures, in coal-based power plants. A comprehensive study has been done by analysing and comparing the work done by various researchers. Some recent advancements related to coating materials and modification in coating techniques have also been studied. This paper would be helpful for the researchers to get an idea for selecting an appropriate substrate material and coating material for industrial applications.

High Temperature Oxidation of Enamel Coated Low-Alloyed Steel 16Mo3 in Water Vapor

“…The fight against fireside corrosion (and erosion) is mostly conducted through various derivate techniques of thermal spray to produce overlay coatings on the different metal alloys (steels and nickel-based alloys) as reported in the comprehensive reviews of Dhand et al [5] and of Kumara and collab. [6].…”

Wear behaviour and microstructural characteristics of cold sprayed nickel-alumina coatings on boiler steel

“…In order to protect it from degradation and enhance its service life, various surface modification techniques such as weld overlays, heat treatments, physical vapor deposition (PVD), chemical vapor deposition (CVD), electroless plating, thermal spray deposition, etc., were found useful [4][5][6]. The thermal spray deposition techniques such as electric arc spray, plasma spray, detonation spray, high-velocity oxygen fuel (HVOF) spray, and cold spray were found highly effective in resisting wear [7]. The thermal spray methods use chemical or electrical energy to melt the feedstock and spray it on the metal surface at high velocities ranging between 800-1200 m/s.…”

Application Of High Velocity Oxy-Fuel Technique To Combat Surface Degradation In Power Generation Industry – A Review

“…In the present study, the literature review of the studies has related to the corrosion and wear resistant performance of the coatings deposited by the high velocity oxy-fuel techniques has been done. There is a wide variety of boiler steels employed at different location of the coal power plant, in the form of machinery such as boilers, reheaters, economizers, superheaters, transportation ducts, draft fans, gates, valves and other structures (Dhand et al, 2021). These steels undergo mild to severe surface degradations at moderate and high temperature operating conditions.…”