Welding and Thermal Spray Processes for Maintenance of Hydraulic Turbine Runners: Case Studies

Abstract: Hydraulic runners are susceptible to failures by cracks or wear erosion, corrosion, cavitation. The modern fabricated in carbon steel and martensitic stainless steel. Arc welding processes normally do the repair of eroded areas, cracked parts. Each material type needs specific criteria, procedures, precautions guarantee their success prevent future issues, like recurrence reduction useful life runner modifications original material. Wear-resistant coatings applied thermal spray processes, considering this last one has no metallurgical interaction with runner, keeping properties For several years companies Copel GeT, Lactec, UTFPR, UFPR collaborate on study different techniques, methods, hydraulic runners, work aims present a short compilation, examples some results obtained real runners.