Computational Design of Corrosion-resistant Gear Steel with Advanced Thermal Processing

High performance gear and bearing materials are necessary to achieve long life and efficient operation of aerospace drive system turbine machinery operating in a marine environment. Current materials capable of providing fatigue and pitting resistance do not provide the desired corrosion resistance. For example, advanced stainless gear alloy Pyrowear 675 has core mechanical properties similar to 9310, but it is difficult to surface-harden while limited due to suboptimal case carburized microstructure and insufficient corrosion resistance. Prior developments to optimize bearing alloy composition and processing have been primarily empirical, an approach that yields diminishing returns when analyzing these complex material systems. QuesTek Innovations LLC proposes to to computationally design and develop a stainless, case-hardened gear and bearing alloy. Property and processing requirements will be defined in collaboration with OEM drive system manufacturers and Navy technical experts. The rapid alloy design will leverage existing materials models and alloy microstructure and processing concepts at QuesTek. Technical feasibility will be demonstrated in the Phase I program with hardness and corrosion testing of solution nitrided sub-scale and laboratory scale prototypes. During the Phase II program, the manufacturing will be scaled up in collaboration with end-users and manufacturing partners to accelerate the technology adoption.