Maraging 300,Maraging C300,UNS K93160,E FORU

### **Maraging 300 / Maraging C300 / UNS K93160** **Ultra-High Strength Nickel-Maraging Steel for Critical Aerospace and Defense Applications** --- #### **1. Overview** **Maraging C300** is a premium-grade 18% nickel maraging steel representing the highest strength level in the commercial maraging steel family. This ultra-high strength steel achieves its exceptional mechanical properties through a combination of martensitic transformation and age-hardening precipitation. Designed to provide an optimal balance of strength exceeding 2000 MPa (300 ksi), reasonable fracture toughness, and good fabricability, Maraging C300 is the material of choice for the most demanding aerospace, defense, and tooling applications where maximum strength-to-weight ratio is critical. --- #### **2. Chemical Composition (Weight %)** The typical chemical composition of Maraging C300 is outlined below. The balance is Iron (Fe). | Element | Content (%) | Key Function | | :--- | :--- | :--- | | **Iron (Fe)** | Balance | Forms the soft martensitic matrix prior to aging. | | **Nickel (Ni)** | 18.0 - 19.0 | Primary element enabling martensitic transformation and precipitation hardening. | | **Cobalt (Co)** | 8.5 - 9.5 | Promotes the formation of Mo-rich precipitates and enhances strength. | | **Molybdenum (Mo)** | 4.5 - 5.2 | Principal precipitation hardening element forming Ni₃Mo intermetallics. | | **Titanium (Ti)** | 0.5 - 0.8 | Forms Ni₃Ti precipitates contributing significantly to strength. | | **Aluminum (Al)** | 0.05 - 0.15 | Aids in deoxidation and forms hardening precipitates. | | **Carbon (C)** | 0.03 max | Kept extremely low to ensure toughness and weldability. | | **Manganese (Mn)** | 0.10 max | Controlled impurity. | | **Silicon (Si)** | 0.10 max | Controlled impurity. | | **Sulfur (S)** | 0.010 max | Minimized to prevent hot shortness. | | **Phosphorus (P)** | 0.010 max | Minimized to prevent embrittlement. | | **Boron (B)** | 0.003 max | Trace addition to enhance hardenability. | | **Zirconium (Zr)** | 0.01 max | Optional addition for grain refinement. | --- #### **3. Physical Properties** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.10 g/cm³ (0.293 lb/in³) | | **Melting Point** | ~ 1410 - 1450 °C (2570 - 2640 °F) | | **Modulus of Elasticity (Young's Modulus)** | 185 GPa (26.8 x 10⁶ psi) | | **Poisson's Ratio** | 0.30 | | **Thermal Conductivity** | 19.0 - 21.5 W/m·K at 20-200°C | | **Mean Coefficient of Thermal Expansion** | 20 - 200°C: **10.3 x 10⁻⁶/°C** (5.7 x 10⁻⁶/°F) | | **Electrical Resistivity** | 0.65 μΩ·m at 20°C | | **Specific Heat Capacity** | 460 J/kg·K at 20°C | --- #### **4. Mechanical Properties (Typical for Aged Condition - 480°C/900°F)** | Property | Value at Room Temperature | | :--- | :--- | | **Tensile Strength** | 2000 - 2070 MPa (290 - 300 ksi) | | **Yield Strength (0.2% Offset)** | 1930 - 2000 MPa (280 - 290 ksi) | | **Elongation (in 50 mm / 2 in)** | 6 - 8% | | **Reduction of Area** | 35 - 40% | | **Fracture Toughness (K_Ic)** | 50 - 70 MPa√m | | **Hardness** | 52 - 54 HRC | | **Charpy V-Notch Impact** | 12 - 18 J (9 - 13 ft-lb) | | **Shear Strength** | 1170 - 1240 MPa (170 - 180 ksi) | | **Fatigue Strength (10⁷ cycles)** | 620 - 690 MPa (90 - 100 ksi) | --- #### **5. International Standards** Maraging C300 conforms to the following international specifications: * **AMS:** * **AMS 6514:** Steel Bars, Forgings, and Tubing 18Ni (300) * **ASTM:** * **A538:** Standard Specification for Maraging Steel Bars, Plates, and Forgings * **MIL:** * **MIL-S-46850:** Maraging Steel Plate, Sheet, and Strip * **UNS:** K93160 * **Aerospace Standards:** * Various proprietary specifications from major aerospace manufacturers --- #### **6. Product Applications** Maraging C300 serves critical functions in the most demanding applications: * **Aerospace Systems:** * Rocket motor cases and missile bodies * Aircraft landing gear components * Space vehicle structural members * Helicopter rotor hubs and components * **Defense Applications:** * Weapon system components * Armor piercing applications * Military aircraft critical structures * Naval vessel components * **Tooling and Manufacturing:** * High-performance die casting tools * Precision molds and fixtures * Extrusion rams and components * Plastic injection molds * **Specialty Engineering:** * High-performance racing components * Critical fasteners and bolts * Nuclear reactor components * High-pressure vessel applications --- #### **7. Key Characteristics & Advantages** * **Ultra-High Strength:** Exceptional strength-to-weight ratio with yield strength exceeding 1930 MPa (280 ksi) * **Excellent Strength-to-Toughness Balance:** Maintains reasonable fracture toughness at the 300 ksi strength level * **Good Fabricability:** Can be machined and formed in the solution-annealed condition with relative ease * **Minimal Distortion:** Simple heat treatment process with minimal dimensional changes during aging * **Superior Weldability:** Excellent welding characteristics without requiring preheating or complex post-weld heat treatment * **Simple Heat Treatment:** Straightforward age hardening at 480°C (900°F) provides consistent, reproducible properties * **Good Corrosion Resistance:** Better resistance to stress corrosion cracking than conventional high-strength steels * **High Temperature Stability:** Maintains mechanical properties at moderately elevated temperatures * **Excellent Fatigue Performance:** Good resistance to cyclic loading conditions * **Proven Reliability:** Extensive successful use in critical aerospace and defense applications --- **Disclaimer:** *The values provided are typical and for informational purposes only. For critical applications, always consult the official material data sheets from the supplier and relevant design codes. Proper solution treatment at 815°C (1500°F) followed by aging at 480°C (900°F) for 3-6 hours is essential for achieving optimal mechanical properties.*

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1699 gallon liquid totes Special package is available on request.