Development and implementation of robotized wire arc additive repair of a gas turbine diaphragm

Abstract

Current practice of reconstruction of oxidized turbine parts (due to hot corrosion) using arc welding methods allows restoration of the nominal shapes and dimensions, as well as other attributes and features. Intense development of 3D additive methods and techniques contributes to repair/ modification of different parts including Gas Turbine (GT) hardware. The article proves viability of the concept of using robotized additive arc welding Metal Active Gas (MAG) process to repair and modify Gas Turbine diaphragms using different filler materials from the substrate. The industrialized robotic additive process (hybrid repair) shows that very good results have been achieved if the diaphragm is cast of nickel iron and the filler material for welding the passes is an austenitic stainless steel (for instance 308 LSi). This is one of the novelties introduced to the repair process that has been granted patent (US11148235B2) and is already implemented to General Electric Service Centers.