Maraging 350,Maraging C350,,E FORU

### **Maraging 350 / Maraging C350** **Ultra-High Strength Nickel-Maraging Steel for Extreme Performance Applications** --- #### **1. Overview** **Maraging C350** represents the ultra-high strength grade within the 18% nickel maraging steel family, designed to deliver exceptional strength levels exceeding 2400 MPa (350 ksi) while maintaining reasonable toughness and excellent fabricability. This advanced maraging steel achieves its extraordinary mechanical properties through a sophisticated precipitation hardening mechanism in a low-carbon martensitic matrix. Maraging C350 is specifically engineered for applications where maximum strength-to-weight ratio is paramount and where conventional high-strength steels cannot meet the demanding performance requirements. --- #### **2. Chemical Composition (Weight %)** The typical chemical composition of Maraging C350 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)** | 11.5 - 12.5 | Critical for enhancing precipitation kinetics and maximizing strength. | | **Molybdenum (Mo)** | 4.5 - 5.2 | Principal precipitation hardening element forming Ni₃Mo intermetallics. | | **Titanium (Ti)** | 1.2 - 1.5 | Major strengthening element forming Ni₃Ti precipitates. | | **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** | 18.5 - 20.5 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** | 0.68 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** | 2350 - 2450 MPa (340 - 355 ksi) | | **Yield Strength (0.2% Offset)** | 2280 - 2380 MPa (330 - 345 ksi) | | **Elongation (in 50 mm / 2 in)** | 4 - 6% | | **Reduction of Area** | 25 - 35% | | **Fracture Toughness (K_Ic)** | 30 - 50 MPa√m | | **Hardness** | 56 - 58 HRC | | **Charpy V-Notch Impact** | 8 - 12 J (6 - 9 ft-lb) | | **Shear Strength** | 1380 - 1450 MPa (200 - 210 ksi) | | **Fatigue Strength (10⁷ cycles)** | 550 - 620 MPa (80 - 90 ksi) | --- #### **5. International Standards** Maraging C350 conforms to the following international specifications: * **AMS:** * **AMS 6516:** Steel Bars, Forgings, and Tubing 18Ni (350) * **ASTM:** * **A538:** Standard Specification for Maraging Steel Bars, Plates, and Forgings * **MIL:** * **MIL-S-46850:** Maraging Steel Plate, Sheet, and Strip * **Aerospace Standards:** * Various proprietary specifications from major aerospace manufacturers * **Tooling Standards:** * Industry specifications for high-performance tooling applications --- #### **6. Product Applications** Maraging C350 is reserved for the most demanding applications where extreme strength is critical: * **Aerospace Systems:** * Rocket motor cases for space launch vehicles * Missile body structures and components * Aircraft landing gear critical components * Space vehicle structural members * **Defense Applications:** * Armor piercing penetrators * Weapon system components * Military aircraft critical structures * Specialized defense applications * **Tooling and Manufacturing:** * High-performance die casting tools * Precision molds for advanced composites * Extrusion rams and components * Plastic injection molds for high-volume production * **Specialty Engineering:** * High-performance racing components * Critical fasteners and bolts * Nuclear reactor components * High-pressure vessel applications --- #### **7. Key Characteristics & Advantages** * **Exceptional Ultra-High Strength:** Unmatched strength-to-weight ratio with yield strength exceeding 2280 MPa (330 ksi) * **Optimized Strength-Toughness Balance:** Maintains reasonable fracture toughness at the 350 ksi strength level * **Excellent Fabricability:** Can be machined and formed in the solution-annealed condition * **Minimal Heat Treatment Distortion:** Simple aging process with minimal dimensional changes * **Good Weldability:** Suitable for welding with proper procedures and without preheating requirements * **Simple Heat Treatment:** Straightforward age hardening provides consistent, reproducible properties * **Good Thermal Stability:** Maintains mechanical properties at moderately elevated temperatures * **Superior Fatigue Performance:** Good resistance to cyclic loading conditions despite ultra-high strength * **Excellent Wear Resistance:** High hardness provides superior wear characteristics * **Proven Performance:** Established track record 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. Special consideration should be given to the reduced toughness at this strength level during design and application.*

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 1700 gallon liquid totes Special package is available on request.