Major Hot Section Component Salvaged through Advanced Repair Methods

This paper describes Pratt & Whitney Aircraft's refurbishment method for upgrading in-service JT9D low pressure turbine cases with a redesigned front flange section of the case. Refurbishment was made possible by the development of electron beam welding techniques for the forged Incoloy 901 nickel-base alloy in the case. The techniques developed minimize heat affected zone intergranular stress cracks which historically have been a deterent to structural welds in Incoloy 901.