Abstract: A gas turbine engine is disclosed having a turbine, one or more hydrocarbon gas combustors, and a compressor. The compressor has a rotor assembly with one or more rotor blade rows extending radially outward from an inner wheel disk. The compressor also has a stator assembly with one or more stator vane rows extending radially inward from an inner casing and positioned between adjacent rotor blade rows. The inner casing extends circumferentially around the rotor assembly and is constructed from at least one low-alpha metal alloy.