REPAIR SURFACING OF GAS TURBINE ENGINE BLADES FROM HIGH-TEMPERATURE NICKEL ALLOYS WITH SURFACE DEFECTS AND DAMAGE

摘要

The main types of defects and damage were determined based on studying full-scale gas turbine blades after manufacture and operation. Most of the defects are located on the surface. The possibility is shown for performance of operations on their elimination by electron beam surfacing with filler of the same composition as that of the blade. Relationship temperature-time of parameters of formation of repair welds, their dimensions and geometry was established. The technological schemes were determined for providing the temperature-time and crystallographic orientation conditions of preservation of single-crystal structure in repair of high-temperature nickel alloy blades. The peculiarities of formation of welds, and their structure, depending on technological parameters of the process of electron beam surfacing were investigated. The methods of practical realization of the obtained results in repair of blade areas of various crystallographic orientation were developed and tested. Examples of repair of blades with structural defects of airfoil surface and damage of edges are given, when restoration of initial geometry, crystallographic orientation and single-crystal structure is provided.