Metallurgical Analysis and Conservation of Turbine Blades from Recovered Apollo F-1 Engines

Abstract

ABSTRACT Turbine blades recovered from the Apollo Saturn V rocket F-1 engines were examined to determine an appropriate conservation protocol. Significant corrosion damage was observed in the turbine blades which appear to be made of a nickel based γ–γ′ superalloy. Pitting corrosion appears to have breached the surface of the turbine blades, and subsequently a form of dealloying corrosion preferentially attacked the γ′ phase. This corrosion left behind a thin network of interconnected γ phase, causing a severe loss of density of the blades and fragility of the blades. The particular alloy used for these turbine blades does not appear to be a known production alloy and may have been developed specifically for use in the F-1 rocket engines, with an increased concentration of refractory (Mo, Nb) elemental additions. The analytical results helped conservators determine a suitable treatment protocol for more than 400 blades and 100 fragments from four recovered turbines.