Industrial Gas Turbines (IGT) demand the highest level of protection to withstand extreme heat and corrosion. At Flame Spray Technologies (FST), we help you boost efficiency and extend component life with our specialized thermal spray coating equipment. As a market leader among other thermal spray companies, we provide the equipment and expertise for coating and refurbishing of components such as turbine blades, and combustion chamber and transition pieces.
Land-based gas turbines components are subjected to high mechanical loads at elevated temperatures, whilst having to contend with hot gas corrosion and erosion from aggressive air and fuel contaminates. For protection from these damaging environments, special thermal sprayed coatings have been developed. These coating extend operating life, and allow increased turbine entry temperatures (TET), leading to an improvement in thermal efficiency.
Overlay Coatings
Turbine blades and guide vanes are generally engineered from either high-temperature resistant nickel-based super-alloys, such as IN738, which have good oxidation-resistant properties but are not capable of withstanding high-temperature corrosion and erosion, or cobalt-based alloys that are excellent against corrosion but have a low resistance to oxidation. To alleviate these problems components are coated with an MCrAlY overlay, the composition of which, and especially the metal component M (Ni, Co, Fe or a combination thereof), depends on the application and the environment in which it is used. MCrAlY alloys form internal oxide structures and spinels, which renders them with excellent resistance to high-temperature oxidation and hot corrosion. The life of the coating is closely related to the oxide content, porosity and the bonding of the coating to the substrate. The addition of yttrium (Y) to the coating improves the overall oxide structure and tenacity of the oxide films.
Thermal Barrier Protection (TBC)
Some components operate in temperature regimes exceeding the maximum allowed for either the overlay coating or the component material, which leads to a requirement for thermal protection. Zirconia based ceramics are applied over the MCrAlY coating to provide a temperature gradient between the gas stream and substrate. With the aid of cooling gases, these components can withstand the elevated gas stream temperatures. The thickness of the zirconia required depends upon the gas stream temperature and the amount of cooling available. These coatings can be applied to a thickness of 2 mm, although typical thickness’ is in the range of 0,2 mm to 0,5 mm.
Thermal spray coatings for industrial gas turbines produce substantial benefits. These include:
- Oxidation and corrosion resistance
- Low thermal conductivity
- Enhanced erosion resistance
- Longer duty cycle and increased part life
- Reduction of substrate operating temperature, resulting in lower thermal and creep stresses
- Protection against hot spots
- Enhanced operating temperature, resulting in increased thermal efficiency
Do you need thermal spray equipment or services?
STS Group – your global partner in enhancing turbine performance and durability
Whether you are looking for thermal spray equipment or services, the companies within the STS Group provide the right solution. From initial consultation to the design and delivery of specialized thermal spray equipment and coating services, the STS Group is committed to supporting your success!
Thermal spray equipment and materials - FST
Are you looking for turnkey thermal spray systems or specialized HVOF, plasma, cold spray, arc wire, flame powder or flame wire spray equipment? FST designs and builds these systems specifically tailored to your application. In addition, FST also supplies thermal spray powders and spare parts.
Thermal spray services - EPC
If you prefer to outsource your coating work, Engineered Performance Coatings (EPC) offers advanced coating services including plasma spraying services, HVOF spraying services, arc wire spraying services and flame spray coating services.
info@fst.nl
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