Repair method for turbine blades

A method for repairing worn guide blades of a gas turbine, the method consisting of the steps of:

• providing at least one worn guide blade to be repaired;
• the at least one worn guide blade having an original state with an original geometry prior to use in the gas turbine and an actual worn state after use in the gas turbine;
• capturing a desired geometry of the at least one worn guide blade;
• the desired geometry being an approximation of the original geometry;
• capturing an actual geometry of the at least one worn guide blade to be repaired in the actual worn state prior to any subsequent processing of the at least one worn guide blade using at least one contactless measuring method;
• comparing the actual geometry of the at least one worn guide blade captured by the at least one contactless measuring method to the desired geometry for a corresponding guide blade type;
• calculating a target geometry for the at least one worn guide blade to be repaired, which corresponds as closely as possible to the desired geometry, such that using optimization parameters, the desired geometry of the at least one worn guide blade to be repaired is approximated at least in sections along its flow contour;
• applying material on the at least one worn guide blade to be repaired and subsequently removing excess applied material by machine, such that the calculated target geometry is produced to provide an at least one repaired guide blade;
• the target geometry of the at least one worn guide blade to be repaired being calculated and reestablished wherein a flow contour in a region of an A4 cross section of the at least one repaired guide blade approximates a flow contour of the desired geometry in the region of the A4 cross section, the A4 cross section being located along a connecting line between a rear edge region of a pressure side of a first guide blade and a central region of a suction side of an adjacent second guide blade.