{"id":4598,"date":"2024-10-31T11:32:05","date_gmt":"2024-10-31T03:32:05","guid":{"rendered":"https:\/\/turbineblade.net\/?p=4598"},"modified":"2025-05-20T13:38:43","modified_gmt":"2025-05-20T05:38:43","slug":"precision-repair-of-gas-turbine-single-crystal-blades-the-key-to-improved-performance-and-reliability","status":"publish","type":"post","link":"https:\/\/turbineblade.net\/fr\/precision-repair-of-gas-turbine-single-crystal-blades-the-key-to-improved-performance-and-reliability\/","title":{"rendered":"Precision repair of gas turbine single crystal blades: The key to improved performance and reliability"},"content":{"rendered":"

Advances in turbine blade technology have increased the cost of new components. The cost of a single crystal blade <\/a>is two to three times that of a conventional cast blade of similar size and complexity. The high cost of a single crystal component can incentivize the owner to maximize the service life of the component.<\/p>

\"\"<\/figure>

As a solution to reduce the cost of replacing components, our company has created processes designed to extend the life of components. One such process is full solution regenerative heat treatment (FSR). FSR restores the microstructure and mechanical properties of the alloy to a new state. The main problem of heat treatment of single crystal alloy FSR is the formation of recrystallized grains on the surface with residual stress. This is a risk given the low content of grain boundary strengthening alloy additives in single crystal alloys. Recrystallization and\/or stray grains in single crystal alloys result in reduced fatigue life and stress break strength at high temperatures. As a result, they are inspected by the original manufacturer and rejected. This is one of the factors for the price rise of single crystal castings!<\/p><\/div><\/div>

Our companyconducted a trial repair to further evaluate the feasibility of FSR heat treatment of single crystal turbine blades, during which it was crucial to ensure that the critical surfaces of the blades did not undergo plastic deformation to avoid subsequent recrystallization. In addition, it is necessary to use effective non-destructive testing methods to check the recrystallization of critical surfaces. Demonstration repair and destructive analysis were performed using a retired Siemens SGT-100 HP turbine blade composed of CMSX-4 single crystal alloy, as shown in Figure 2. The blades were in operation for 28,000 hours. After one repair, it operated for another 12,000 hours. Total service time is 36,000 hours and the OEM notifies the operator that the part has expired!<\/p><\/div>

\"\"