Gat No. 129, Near SM Mart, Ganesh Nagar, Talawade, Pune - 411062, Maharashtra, India
In terms of growth and development, the power generation industry is the foundation of any nation. This industry has always been under intense pressure to deliver clean, sustainable energy in the most economical and efficient manner possible, despite the fact that the process is rather traditional and requires a highly developed system to get the necessary results.
A few technologies, such as steam turbines, gas turbines, hydropower plants, etc., transform traditional thermal, wind, or fluid energy into usable power in its raw form. Nevertheless, these power plants experience significant high-temperature corrosion and erosion of vital components, which is mostly caused by aggressive gasses such as H2S, HCl, and others, frequently in conjunction with metal and alkali chlorides that are created during the burning of fuel. Thermal spray coatings based on ceramic, carbide, and cemet play a major role in extending the lifetime and performance of components, hence boosting power plant thermal and electrical efficiency.
Thermal spray coatings (MCrAlY bond coats and thermal barrier coatings) protect turbine blades, diaphragms, and hot-gas-path components from solid particle erosion (SPE) and hot oxidation.
High-temperature erosion-resistant coatings applied via HVOF shield superheater and reheater boiler tubes from aggressive fly ash erosion and gas-phase corrosion.
Specialized dense coatings protect vital plant components from chemical degradation caused by combustion gases like H2S, HCl, and alkali chlorides.
Ceramic, carbide, and cermet coatings extend critical component service life by 3–5×, minimizing forced outages and boosting overall thermal and electrical output.
| Plant area | What damages it | Surface solution |
|---|---|---|
| Boiler tubes | Fly-ash erosion and high-temperature corrosion | Chromium carbide nickel chrome coating by HVOF |
| Steam turbines | Solid particle and water droplet erosion | Carbide coatings; Stellite on leading edges |
| Gas turbines | Heat and oxidation in the hot gas path | Thermal barrier coatings over MCrAlY bond coats |
| Hydro turbines | Silt erosion and cavitation | Tungsten carbide coating by HVOF |
| Steam and feedwater valves | Erosion and galling of seats | Stellite hardfacing, lapped sealing faces |
| Boiler feed and slurry pumps | Abrasion of sleeves and wear rings | Carbide or ceramic coatings |
Rivers fed from the Himalayas carry large quantities of hard quartz silt in the monsoon months, and it wears turbine runners, guide vanes and labyrinth seals quickly. Hard, dense HVOF tungsten carbide coatings on these surfaces are widely used to extend the interval between overhauls.
Many components can be reclaimed rather than replaced: worn surfaces are built back up, coated and ground to size while the unit is down. Sharing drawings and the outage window early lets the work be planned to fit it. See also our pump and valve coating solutions.
Boiler tubes, steam and gas turbine parts, hydro turbine runners and guide vanes, steam and feedwater valve trim, and pump sleeves and wear rings are all commonly coated. Each faces a different combination of erosion, corrosion and heat, so the coating material differs for each.
Superheater and reheater tubes are protected with a chromium carbide nickel chrome coating applied by HVOF. The coating keeps its hardness at boiler temperatures and resists both the erosion of fly ash and corrosion from hot combustion gases.
Hard, dense tungsten carbide coatings applied by HVOF are widely used on runners, guide vanes and labyrinth seals. They resist the quartz silt that rivers carry in the monsoon months and extend the interval between turbine overhauls.
Steam valve seats and discs are usually hardfaced with Stellite, a cobalt alloy that resists erosion and galling and keeps its hardness when hot. The faces are then ground and lapped to give a tight metal-to-metal seal.
Yes. Worn components can often be reclaimed during an outage: the surface is built up, coated and ground back to size. Sharing drawings and the outage dates in advance lets the work be planned to fit the window.
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