Land-based gas turbines components are subjected to high mechanical loads at elevated temperatures while having to contend with hot gas corrosion and erosion from aggressive air and fuel contaminates. For protection from these damaging environments, special laser clad 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 usually engineered from either high-temperature resistant nickel-based super-alloys or cobalt-based alloys. Nickel-based super-alloys such as IN738 have excellent oxidation-resistant properties but are not capable of withstanding high-temperature corrosion and erosion. Cobalt-based alloys are excellent against corrosion but have a low resistance to oxidation. Laser cladding is used by OEM’s and repair facilities globally as the chosen process for blade repair and turbine overhaul applications.
Laser Cladding for industrial gas turbines produces substantial benefits. These include:
- Oxidation and corrosion resistance
- 3D printing of components
- Enhanced erosion resistance
- Manufacture & repair applications
- Longer duty cycle and increased part life
- Reduction of NOx emissions