Recovery of Hydro Turbines: From Welding to Additive Manufacturing

Abstract

This work describes the advances in manufacturing for the recovery of hydraulic turbines. One of the key components in the operation of hydraulic turbines is the blades; as they are part of the impeller, they are in constant motion and directly receive all the loads produced by the impact of the water and the abrasive effects caused by sediment. The interaction between abrasion, cavitation, and corrosion accelerates the wear of these components, so it is necessary to apply coatings to prolong their useful life. When these elements lose their hydrodynamic profile, they must be submitted to a recovery process; typically, welding is used. However, due to the advancement of additive manufacturing (AM) and the development of new materials, AM appears as a disruptive technology capable of recovering the dynamic profile and improving surface properties such as hardness and wear resistance. The results show the effectiveness of the wire and arc additive manufacturing technology for the recovery of hydraulic turbines, increasing surface hardness from 285 to 325 HB.