Application of Local Hard Fillet Weld to Repair Damage Caused by Cavitation in Hydroelectric Power Plant

摘要

Hydroelectric power plants come into prominence worldwide day by day due to their low operating and maintenance costs, environment friendly structure and their use as renewable energy sources. In order to obtain maximum energy from such an important energy source, it is necessary to reduce downtime due to failures. One of the most important failures of hydroelectric power plants is the damage caused to the turbine wheel by cavitation. In this study, a sample with the same material as the turbine wheels of the hydroelectric power plants is provided. The effects of the hard fillet weld on the turbine wheel, which we have applied locally to this material, have been investigated both metallographically and physically. As a result of the research, it is observed that the main material and hard fillet weld are mostly compatible. The damages of the turbine wheel of the hydroelectric power plant have been repaired by applying the same method to the turbine wheel damaged by the cavitation. After 10,000 h of operation, the turbine wheel is inspected again. As a result, it has been determined that the hard fillet weld applied to the turbine wheel surface is resistant to the harmful effects of cavitation.