Optimized Corrosion Resistant Bearing and Gear Steel Thermal Processing

Pyrowear® 675 is noted as a high performance bearing material used in turbine engine and other higher temperature applications. The mechanical properties and stability necessary for these applications is achieved via carburizing by design. The carbides that form to provide the hot hardness and desired mechanical properties for bearing service are at the expense of corrosion resistance. As the carbides form during carburizing, the alloying elements responsible for much of the corrosion resistance are removed from solution. When the alloying elements are tied up in carbide phases, the corrosion protection is drastically reduced. With the current thermal processing methods, the corrosion protection cannot be maintained when the hardness requirements are met. IBC Materials and Technologies will develop innovative thermal processing technologies based on solution nitriding and a vacuum carburizing with post-low temperature ion plasma nitrocarburizing. This solution will achieve an expanded S-phase austenite (S-phase) in the Pyrowear® 675, leading to superior hardness and corrosion resistance of the bearings and gears.