QuesTek® Innovations Ferrium® S53® Corrosion Resistant High Strength Steel for Aerospace Structural Applications

Description: Ferrium® S53® is a corrosion resistant ultra high-strength steel for structural aerospace applications. Ferrium® S53® was designed to provide mechanical properties equal to, or better than, conventional ultrahigh-strength steels such as 300M and SAE 4340 with the added benefit of general corrosion resistance. This eliminates the need for cadmium coating processes, which are environmentally unfriendly and require subsequent hydrogen bake-out operations in order to avoid hydrogen embrittlement. Ferrium® S53® has a greatly improved resistance to stress-corrosion cracking (SCC) over 300M and SAE 4340. Ferrium® S53® utilizes an efficient M2C strengthening dispersion precipitated through tempering while avoiding other carbides. This maximizes strength, wear resistance, and toughness; resulting in a unique combination of mechanical properties for a corrosion resistant steel. Ferrium® S53® uses a stable passive oxide film for optimum corrosion resistance. It also has high hardenability, permitting less severe quench conditions for a given section size and resulting in less distortion during heat treatment. S53® should be considered for use in applications requiring high strength with good fracture toughness, corrosion resistance and high resistance to stress-corrosion cracking (per ASTM F1624). S53® is supplied in a normalized and annealed condition. The dimensional change upon hardening from the annealed condition is approximately 0.003 in./in.Typical Applications: Aircraft landing gears, flap tracks, actuators, fasteners and other structural applications.Workability:Fording: Forge at 2050°F (1121°C) followed by an air cool, normalize, subzero treatment and anneal.Machinaility: Annealed Ferrium® S53® has machinabilty similar to 300M at 35 HRC.Passivation: Passivation in a 50% nitric acid solutions recommended for maximum corrosion resistance per AMS 2700B, Method 1Heat Treatment:Solution Treatment: 1985°F(1085°C) 1 hour and oil quench or equivalent, water quenching is not recommended. Soak time must be closely monitored, load couples are recommended.Sub Zero Treatment: Following the solution treatment, -100°F(-73°C), 1 hour and air warm.Tempering: 934°F (501°C), 3 hours and oil quench or equivalent followed by -100°F(-73°C), 1 hour and air warm then a second temper at 900°F(482°C) 12 hours and air cool.Other Key PropertiesCorrosion resistance has been measured using a variety of test methods. General corrosion resistance of S53® is similar to 440C.Fatigue testing at a number of R values and stress levels has shown equivalent performance to typical 300M values.S53® yields a Class A Weld. Welding studies have shown minimal impact on mechanical properties.Product Forms: Ferrium® S53® may be manufactured in typical ingot, bar, and billet forms. Sheet and plate also available upon request.Ferrium is designed by Questek Innovations, LLC. and is manufactured by Latrobe Specialty Steel under license.