Coil steel Freeflex™

for the aerospace industry

Freeflex™ is a hardened and tempered martensitic stainless compressor valve steel alloyed with copper. The material is characterized by: Excellent combination of high strength and high ductility Extremely high fatigue strength under bending and impact stress Excellent surface finish Very high compressive residual surface stress Low level of non-metallic inclusions Very good wear resistance Freeflex™ compressor valve steel has excellent dimensional tolerances and flatness. Chemical composition (nominal) Chemical composition (nominal) % C - Si - Mn - P - S - Cr - Mo - Cu 0.53 - 0.40 - 0.68 - ≤0.025 - ≤0.010 - 14.0 - 1.00 - 0.70 Applications Valve types: Flapper valves Reed valves Check valves Fabrication Tumbling A good tumbling operation giving a round, smooth edge is necessary in order to minimize stress concentrations. Tumbling also increases the residual compressive surface stresses which gives a significant further improvement in fatigue properties. Forms of supply Conditions and forms of supply Strip steel is supplied in labeled coils, or on labeled plastic spools, depending on weight and size. The label details the steel grade, heat, lot and coil number, and nominal size, allowing full material traceability. Material is protected against rust with oil.