Maraging 350，Maraging C350 Plate，,E FORU

British Specs:，American Specs: AMS 6515 MIL-S-46850，German Specs: WS 1.6356

### **Product Datasheet: Maraging 350 / Maraging C350 Steel Plate** #### **Overview** Maraging 350 (Maraging C350) Plate is a premium ultra-high-strength, low-carbon martensitic steel supplied in plate form. The "350" signifies its nominal yield strength of 350 ksi (approximately 2413 MPa), achieved through a unique age-hardening heat treatment. This process precipitates intermetallic compounds within a soft, ductile martensitic matrix, resulting in an unparalleled combination of strength, toughness, and dimensional stability. Maraging C350 Plate is the material of choice for critical structures and components where maximum reliability under extreme static and dynamic loads is required. #### **Key Characteristics & Advantages** * **Ultra-High Strength:** Achieves the highest strength level among commercial maraging steels, with yield strength exceeding 2400 MPa. * **Exceptional Fracture Toughness:** Maintains high resistance to crack propagation despite its extreme strength, a critical safety feature. * **Superior Dimensional Stability:** Exhibits minimal distortion and predictable, minimal dimensional change during the final age-hardening process, which is vital for precision-machined components. * **Excellent Fabricability:** Plates can be machined, welded, and formed in the soft, solution-annealed condition with relative ease before the final, low-temperature aging treatment. * **Good Stress Corrosion Cracking Resistance:** Offers better performance than many other ultra-high-strength steels in demanding environments. --- #### **Chemical Composition (Typical Weight %)** The composition is meticulously balanced to ensure optimal age-hardening response and final mechanical properties. | Element | Content (%) | Element | Content (%) | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | 18.0 - 19.0 | **Cobalt (Co)** | 11.5 - 12.5 | | **Molybdenum (Mo)**| 4.6 - 5.2 | **Titanium (Ti)** | 1.3 - 1.6 | | **Carbon (C)** | ≤ 0.03 | **Manganese (Mn)** | ≤ 0.10 | | **Silicon (Si)** | ≤ 0.10 | **Sulfur (S)** | ≤ 0.010 | | **Phosphorus (P)** | ≤ 0.010 | **Aluminum (Al)** | 0.05 - 0.15 | | **Boron (B)** | 0.003 - 0.005 | **Zirconium (Zr)** | 0.01 - 0.02 | | **Iron (Fe)** | **Balance** | | | --- #### **Physical & Mechanical Properties** **Physical Properties** * **Density:** 8.10 g/cm³ (0.292 lb/in³) * **Melting Point:** ~ 1410°C (2570°F) * **Thermal Expansion Coefficient (20-100°C):** 10.2 x 10⁻⁶/°C * **Modulus of Elasticity:** 185 - 190 GPa (27 x 10⁶ psi) **Mechanical Properties (After Full Heat Treatment: Solution Annealed & Aged)** *Typical values for aged plate material. Properties can be adjusted via specific aging parameters.* | Property | Typical Value | Condition | | :--- | :--- | :--- | | **Tensile Strength** | 2450 - 2550 MPa (355 - 370 ksi) | Aged | | **Yield Strength (0.2% Offset)** | 2340 - 2410 MPa (340 - 350 ksi) | Aged | | **Elongation (in 2 inches / 50mm)** | 8 - 12 % | Aged | | **Reduction of Area** | 35 - 50 % | Aged | | **Hardness** | 54 - 57 HRC | Aged | | **Fracture Toughness (K_Ic)** | 55 - 80 MPa√m | Aged | *Note: In the solution-annealed and annealed condition (soft state), the plate has a hardness of approximately 28-32 HRC, making it suitable for heavy machining, cutting, and welding operations.* --- #### **International Standards & Specifications** Maraging C350 Plate is governed by stringent international standards, primarily within the aerospace sector. * **AMS (Aerospace Material Specification):** * **AMS 6521G:** This is the primary and most relevant specification for Maraging 350 Plate. It covers the chemical composition, heat treatment cycles, and mechanical property requirements for sheet, strip, and plate. * **ASTM (American Society for Testing and Materials):** * **ASTM A579/A579M:** Standard Specification for Superstrength Alloy Steel Forgings. While focused on forgings, its grades cover maraging steels of similar strength levels and are sometimes referenced. * **U.S. Military Standards:** * **MIL-S-8949:** This specification for Maraging Steel Plate, Sheet, and Strip is a key governing document, especially for defense and aerospace applications. * **Customer-Specific Specifications:** Plates are often produced to meet additional customer-defined requirements for ultrasonic inspection (e.g., to AMS 2631), magnetic particle inspection, or specific through-thickness properties. --- #### **Product Applications** Maraging C350 Plate is utilized in the most demanding structural and component applications across high-technology industries: * **Aerospace & Defense:** * **Rocket Motor Casings:** For solid and liquid propellant rockets, where the plate is formed and welded into high-pressure vessels. * **Aircraft & Spacecraft Landing Gear:** Critical components requiring the ultimate in strength, toughness, and fatigue resistance. * **Airframe Components:** Bulkheads, wing spars, and other primary structures in high-performance military aircraft and space launch vehicles. * **Armor Plate:** For advanced lightweight armored vehicles. * **Precision Tooling & Molding:** * **Injection Molds:** Cavities and cores for high-pressure plastic injection molding, offering high polishability and wear resistance. * **Die-Casting Dies & Cores:** For aluminum and magnesium die-casting, withstanding thermal cycling and erosion. * **Extrusion Die Backers:** Supporting dies in aluminum extrusion presses, requiring high compressive yield strength. * **Specialty Machinery:** * **High-Performance Springs** * **Fasteners and Critical Shafts** --- #### **Conclusion** Maraging C350 Plate stands at the apex of ultra-high-strength steel technology. Its ability to be fabricated in a soft state and then transformed into one of the world's strongest and toughest steels via a simple aging process makes it indispensable for aerospace, defense, and high-performance tooling. For engineers designing against the most extreme forces, Maraging C350 Plate provides a proven, reliable, and weight-efficient foundation for mission-critical applications.

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 2643 gallon liquid totes Special package is available on request.