Improving the Performance of Navy Helicopter Masts by Using Corrosion-Resistant, Ultra-High-Strength Steel

QuesTek will evaluate the feasibility of using Ferrium S53 as the main rotor shaft mast material in Navy helicopters to eliminate the need for toxic cadmium plating, reduce weight and increase toughness (durability), fatigue resistance, general corrosion resistance and SCC resistance. The alloys currently used for Navy helicopter masts (such as 4340 or 9310) provide high strength but offer limited corrosion resistance, and are typically coated (and re-coated during overhaul) with toxic cadmium plating. S53 is a new ultra-high-strength, corrosion-resistant steel developed by QuesTek with its proprietary Materials by Design development process. S53 is commercially available from two U.S.-based suppliers and has received industry certifications, including SAE (AMS5922) and MMPDS approvals. In applying S53 to rotorshaft masts, QuesTek will further develop the surface hardening process developed during the Phase I effort to accommodate gears, splines, bearings and other hard contact points. QuesTek will also produce demonstration components that will be manufactured with the inclusion of the new surface hardening process.