QuesTek Innovations LLC is applying its Materials by Design⑧computational design technology to develop a
new class of high strength, secondary hardening gear steels that are optimized for high-temperature,
low-pressure (ie., vacuum) carburization. The alloys offer three different levels of case hardness (with the
ability to“dial-in” hardness profiles, including exceptionally high case hardness), and their high core strength,
toughness and other properties offer the potential to reduce drivetrain weight or increase power density
relative to incumbent alloys such as AISI 9310 or Pyrowear⑧Alloy 53. This new class of alloys utilizes an
efficient nanoscale M2C carbide strengthening dispersion, and their key benefits include: high fatigue
resistance (in contact, bending, scoring); high hardenability achieved via low-pressure carburization (thus
reducing quench distortion and associated manufacturing steps); a tempering temperature of 900°F or higher
(providing up to a 500°F increase in thermal stability relative to incumbent alloys); and core tensile strengths in
excess of225 ksi. Ferrium@ C61 M is one alloy in this family and is currently used in transaxle ring and pinions
for SCORE⑧1600 class off-road racing cars as well as process equipment applications; C61 is also being
examined in a Army SBIR program as a potential replacement for 9310 in CH-47 Chinook helicopter main
rotor mast applications, yielding a projected potential weight savings of 15- -25%. Secondly, Ferrium C64″M is
being developed under a Navy STTR program aimed at rotorcraft gear transmission applications in order to
reduce weight, improve fatigue performance, and improve high temperature operating capability relative to
the incumbent alloy Pyrowear⑧Alloy 53. Lastly, Ferrium C69 M can achieve a carburized surface hardness of
HRC 67 (with a microstructural substantially free of primary carbides) and has exceptionally-high contact
fatigue resistance, which makes it a candidate for applications such as camshafts and bearings as well as
gear sets.