Repairing components with cavitation damage and restoring them to their original configuration is very important. Dismantling and shipping large components to repair facilities is time consuming and expensive. The ability to conduct repairs insitu has significant and beneficial financial implications. Technology advances now permit the use of semi-automatic and automatic welding as wll as manual techniques to be used. Both quality and financial aspects can be significantly improved. New welding alloys have been developed that provide cavitation resistance superior to many previously used materials. Many of the new alloys offer increased weldability and welder appeal. Alloy options, prop0rties and test data for materials such the Electric Power Research Institutes' NOREM~(TM) and special variations of the 300-series austenitic stainless steels families are presented. Welding process alternatives and appropriate weld filler metals for shielded metal arc welding, gas metal arc welding, flux cored arc welding and strip cladding are discussed from feasibility and application viewpoints. Use of new alloy systems and high deposition welding process variations make it possible to consider composite approaches to material selection - providing both technical and more economical options. Complementary insitu repair technology developed and implemented in the fossil and nuclear power generation and petroleum industries that are useful for hydro-type repairs is highligted. Turbine runners, penstocks, tanner gates and other similar components are all candidates for insitu or at least on site repair.
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