Case-Hardened Gear Steel with Ultrahigh-Strength Core Ferrium® C64tm Chemical Composition (nominal wt. %) Fe Materials By Design® Objective Increased engine power transmission demands high-performance gears. The design objective for Ferrium® C64 was to develop a secondary-hardening gear and bearing steel with superior core and surface properties to current gear steels. Description Ferrium C64 is a member of a new class of martensitic secondary-hardening gear and bearing steels that utilize an efficient M2C precipitate strengthening dispersion. Because of the efficiency of this strengthening dispersion, Ferrium C64 achieves carburized surface hardness (62-64 HRC) superior to current gear steels with the added benefit of increased core properties. A typical hardness profile of carburized Ferrium C64 is shown to the left. Advantages Ferrium C64 has surface-wear properties and fatigue properties superior to those found in current commercial alloys.

FERRIUM® C64 Case-Hardened Gear Steel with Ultrahigh-Strength Core Processing Ferrium C64 was designed for high-temperature carburizing. This allows solution heat treatment to be combined with the carburizing treatment and Ferrium C64 is therefore quenched directly from the carburizing temperature. After quenching to room temperature, Ferrium C64 is subjected to cryogenic treatment to assure a complete martensitic transformation. Ferrium C64 is typically tempered at 925°F (496°C) and has excelle nt thermal resistance approaching this temperature. Case carburizing produces a gradient in the volume...