The final strategic objectives of this project are the reduction of costs of electrical production in Europe and the increase of overall competitiveness of European Industries.
The technical goal of this project is to develop automatic procedures dedicated to repair the damage to turbine components by welding and cladding with a CO2 laser robot. These procedures will include automatic acquisition of damages mapped with conventional methods and self-programming of the robot in order to improve the productivity of the system.
This subsystem will DMSS (Damage Management SubSystem).
This proposal conforms with the aims and the objectives of the following priority themes in the BRITE/EURAM Information Package :
- 4.2.4. development of CO2 laser processing procedures and optical subsystems integrated in robotic structure for welding and surface treatments
- 3.1.3. development of robotic controls for mapping individual damage in each component and then for repairing it by automated cutting, welding and cladding operations as necessary, for economical high integrity refurbishment
- 2.2.3. measurement of service damage contours using non-contact sensors, in the process of refurbishing the component
- 1.1.3. improved creep and fatigue strengths of welded gas turbine components by new, optimized welding processes.
A robotic welding Work Station equipped with a CO2 laser was developed in the Project, integrating a damage monitoring sub-system able to perform a quantitative assessment of the extent, the size and the location of the damage (using a 3D mapping) in high value industrial components. The data resulting by the comparison between the precise 3D contour of the damage with the original topography are used to drive the robotized laser welding device during the repair of the damaged article.
Among the most expensive and critical turbogas parts made of materials with weldability problems, four type of components/materials were chosen for the activity typically affected by different types of damages; both butt-welding of a new insert and cladding were considered, as refurbishment processes.
The CO2 laser robotized system was used to develop repairing procedures to obtain defect-free welds and cladding on the materials of turbine components. Alternative component suitable weld-procedures were also studied for each type of material.
Discriminatory mechanical tests were performed on welded samples obtained with CO2 laser and with the alternative processes. A comparison between these results demonstrates that laser processing gives the best performance in three of the four analyzed materials.
Finally the work station was used to perform automatized refurbishment of real components with the welding procedure developed in the project for the corresponding material class. For these components the cost-effectiveness of the CO2 laser refurbishment system was assessed.