Steam and Land-Based Turbines
Steam and land-based turbines owe their operating efficiency to Metal/Thermal Spray. The video below shows a HVAF system spraying a WC-Co-Cr coating being applied on-site onto steam turbine blades in order to protect them from droplet erosion.
Almost every component of the gas turbine engine has some type of coating on it to prevent the damage caused by wear and temperature. HVAF and HVOF coatings are used in the hot section of the engine to coat the shroud with high temperature metals that will not damage the edge of the engine’s turbine blades, yet provide the tight clearance necessary for the engine to function properly. HVAF and HVOF coatings are also applied to the rotating sleeves or bearing found in the hot section of the engine. Common coatings used in this application include T-800 and Chromium Carbide Nickel Chrome coatings.
The above video shows a Kermetico HVAF AK7 spraying Tungsten Carbide on a turbine floor.
Wind Turbines
From the early era of inland wind towers, thermal spray coatings have been widely used. The tower sections are generally coated with zinc or aluminium in areas where there is a higher probability of coating damage during erection or use of the tower. This includes, but is not limited to - at the flanged ends, around access hatches and ladder supports.
As the towers went off-shore, this meant that they were situated in a harsher corrosion environment which called for a tougher corrosion-resistant coating. Many of the major manufacturers are specifying Metal Sprayed zinc or zinc/aluminium coatings on their towers, nacelles, hubs and slewing rings. The industry is increasingly using Thermal Spray Aluminium (TSA) coatings on monopiles, jacket structures and boat landings (taking learnings from the decades of use in the oil and gas industry).
The above video shows the zinc Arc spray coating process of wind towers (turbines) from blast, thermal spray zinc, prime and top coat.
Pelton Buckets
Pelton Buckets suffer high wear on the internal surface due to silt erosion and cracking on the thinner bucket surface areas cause an imbalance in operation. These are protected by HVOF Spraying or Arc Spraying with 420 Stainless Steel.
For more information on the Turbine Industry, Click Here.
