René N515 is a single crystal nickel-base superalloy containing a reduced rhenium content of 1.5%, positioned between rhenium-free chemistries and full second-generation single crystal alloys. The rhenium provides solid-solution strengthening of the gamma matrix for improved creep capability, while the lower content moderates raw material cost relative to alloys carrying 3% rhenium. Qualified under C50TF130, René N515 is suited to high-pressure turbine blades and first-stage nozzle guide vanes in advanced aerospace and industrial gas turbine engines.