Assemblage métallurgique des pièces moteurs. Soudage par friction inertielle de disques de compresseur HP en superalliage de nickel

Abstract
The main part of this paper describes upside metallurgical and mechanical work done at SNECMA,on inertia welding of powder metallurgy nickel base superalloys ASTROLOY and N18, allowing appliance of this process to engine parts : Inertia welding of superalloys leads to deap microstructural changes in the H.A.Z which have been, as well as upset. correlated to process parameters, weld geometry and base material microstructure ; a full mechanical testing of welds shown properties equivalent to base material ones up to 650 °C except for fatigue crack growth behavior under specific conditions (T>600°c-hold time at maximum load) which is drastically reduced for in weld plane propagation. A significant improvement of this later property has been done through post-welding heat treatment and optimization of welding parameters. Last part of this paper summarize the main teachings gained, on the complete welding procedure, from welding of scale one parts.