The 680 mm (26.75") moving blade {L-O stage) of a 110 MW geothermal steam turbine, suffered tenon and shroud solid particle erosion (SPE) damage which can lead to catastrophic damage of the blades. The development of a welding technology for the in-situ repair of eroded tenons without blade disassembly is fully described. The repair process included the removal of tenons, method of tenon restoration by weld deposition, stress relief and tenon machining to recover their original geometry. The method developed, of in-situ tenon mechanized machining, using a turning and grinding process is a unique in tenon in-situ repair technology. After L-O blade repair, the rotor was put back into service. The approach to repair of tenon erosion damage has been successful, it enabled significant reductions in expenditure on replacement parts and reduction of outage time to be achieved. In another case more than 200 tenons of L-1 moving blades were rebuilt in-situ.
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