In the Space Shuttle Main Engine a nickel "superalloy" called INCONEL 718 was used.
High-Pressure Oxidizer Turbopump - The function of the high-pressure oxidizer turbopump (HPOTP) is to provide a high-pressure, high-volume flow of liquid oxygen to the main injector arid to the preburner injectors sufficient to ensure positive injection of oxidizer at all thrust levels (Figure 8). The HPOTP is a centrifugal pump consisting of a double-entry main impeller and a smaller, single-entry boost impeller on a common drive shaft and develops 16.4 x 7 10 W at 29,000 rpm. The low-pressure oxidizer pump delivers liquid oxygen to the HPOTP main impeller at about 2.9 MPa. The main impeller increases this pressure to almost 35 MPa and most of this flow is directed to the MCC injector. A small portion of this liquid oxygen flow is diverted to the boost impeller which increases the pressure to approximately 55 MPa to feed the prebumers. The main impeller is machined from an alloy 718 closed-die forging and the boost impeller is an alloy 718 precision investment casting. The pump housing, also alloy 718, is a complex welded assembly composed of castings, forgings, and formed sheet. All components are in the solution-treated and aged condition subsequent to welding. Alloy 718 was selected for its high strength, compatibility with liquid oxygen, and good toughness at the operating temperature of -179°C.
