ATI Allvac® VascoMax® C-300 Specialty Steel Wire

ATI Allvac® VascoMax® C-300 Specialty Steel Wire, Heat Treatment: 927°C (1700°F) + Age Product Information -:- For detailed product information, please contact sales. -: ATI Allvac® VascoMax® C-300 Specialty Steel Wire, Heat Treatment: 927°C (1700°F) + Age Synonyms -:- For detailed product information, please contact sales. -:

ATI Allvac® VascoMax® C-300 Specialty Steel, Heat Treatment: 927°C (1700°F) + Age Product Information -:- For detailed product information, please contact sales. -: # ATI Allvac® VascoMax® C-300 Specialty Steel ## Premium Ultra-High-Strength Cobalt-Nickel Maraging Steel | Heat Treated to 927°C + Aged --- ### **Product Overview** ATI Allvac® VascoMax® C-300 (commonly designated as **C-300 or C300**) is a **high-cobalt, nickel-maraging steel** representing the **upper echelon of commercially available ultra-high-strength alloy steels**. Engineered to achieve a nominal yield strength of **300 ksi (≈2068 MPa)**, this grade delivers the **highest practical combination of strength and toughness** in the standard maraging steel hierarchy. The specified heat treatment of **austenitizing at 927°C (1700°F) followed by precipitation aging** develops its exceptional properties, making it the material of choice for the most demanding aerospace, defense, and space applications where **absolute maximum strength-to-weight ratio is required alongside critical reliability and damage tolerance**. --- ### **Chemical Composition (Weight %)** | Element | Min (%) | Max (%) | Typical (%) | Metallurgical Function | |---------|---------|---------|-------------|------------------------| | **Nickel (Ni)** | 18.0 | 19.0 | 18.5 | Forms the tough, ductile lath martensitic matrix; essential for fracture toughness. | | **Cobalt (Co)** | **11.5** | **12.5** | **12.0** | **Critical Driver.** Reduces solubility of Mo in martensite, dramatically increasing the thermodynamic driving force for precipitation hardening, enabling strength > 300 ksi UTS. | | **Molybdenum (Mo)** | 4.6 | 5.2 | 4.9 | Primary precipitation hardener; forms fine, coherent Ni₃Mo intermetallic particles. | | **Titanium (Ti)** | **1.2** | **1.45** | **1.35** | **Key Strengthener.** Substantially increased vs. C-250 grade. Forms abundant Ni₃Ti precipitates, contributing massively to the target 300 ksi strength. | | **Aluminum (Al)** | 0.05 | 0.15 | 0.10 | Deoxidizer; contributes to grain refinement. | | **Carbon (C)** | — | 0.03 | ≤0.01 | Ultra-low to maximize toughness and weldability. | | **Manganese (Mn)** | — | 0.10 | 0.05 | Residual element. | | **Silicon (Si)** | — | 0.10 | 0.05 | Residual element. | | **Boron (B)** | — | 0.005 | 0.003 | Enhances hardenability and grain boundary strength. | | **Zirconium (Zr)** | — | 0.02 | 0.01 | Grain refiner; improves toughness. | | **Sulfur (S)** | — | 0.010 | ≤0.005 | Impurity control. | | **Phosphorus (P)** | — | 0.010 | ≤0.005 | Impurity control. | | **Iron (Fe)** | Balance | — | — | Base element. | **Core Identity:** This is the direct commercial equivalent to **AISI 18Ni(300) / Maraging 300** (UNS K92890). The "C" prefix denotes ATI's proprietary production and quality control. The chemistry is optimized to achieve the **300 ksi (2068 MPa) Ultimate Tensile Strength** benchmark. --- ### **Recommended Heat Treatment** 1. **Austenitizing (Solution Treatment):** * **Temperature:** **927°C (1700°F)** ± 15°C * **Time:** 1 hour per inch of thickness (minimum 1 hour), then **Air Cool**. * **Purpose:** Produces a uniform, soft, low-carbon lath martensite with all alloying elements in solid solution. Hardness: ~30-34 HRC. 2. **Aging (Precipitation Hardening):** * **Temperature:** **482°C (900°F)** ± 5°C * **Time:** 3-6 hours (typically 3-4 hours for sections < 50mm), then **Air Cool**. * **Phenomenon:** Induces the uniform precipitation of fine, coherent intermetallic compounds (Ni₃Mo, Ni₃Ti) within the martensite matrix, increasing strength by over 100% with minimal dimensional change (~0.05% growth). --- ### **Mechanical Properties (After 927°C Austenitize + Aged)** *Typical minimum guaranteed values in peak-aged condition (Longitudinal direction).* | Property | Minimum Guaranteed | Typical Achieved | Test Standard | |----------|-------------------|------------------|---------------| | **Ultimate Tensile Strength (UTS)** | **2000 MPa (290 ksi)** | 2060 - 2140 MPa (299 - 310 ksi) | ASTM E8 | | **0.2% Yield Strength (YS)** | **1900 MPa (276 ksi)** | 1960 - 2050 MPa (284 - 297 ksi) | ASTM E8 | | **Elongation (in 50 mm)** | 8% | 10 - 12% | ASTM E8 | | **Reduction of Area (RA)** | 45% | 50 - 60% | ASTM E8 | | **Hardness** | 50 HRC | 52 - 54 HRC | ASTM E18 | | **Fracture Toughness (K_IC)** | **70 MPa√m** | 75 - 90 MPa√m | ASTM E399 | | **Modulus of Elasticity** | 180 GPa (26.1 x 10⁶ psi) | 185 - 190 GPa | ASTM E111 | | **Fatigue Strength (10⁷ cycles, R=0.1)** | Report | 600 - 700 MPa | ASTM E466 | **Key Performance Balance:** The **~2000 MPa UTS combined with ~80 MPa√m K_IC** represents the optimal balance for most ultra-high-strength applications, offering a superior **strength-toughness product** that is the hallmark of this grade. --- ### **Physical Properties (Aged Condition, 20°C)** | Property | Value | |----------|-------| | **Density** | 8.01 - 8.03 g/cm³ (0.289 lb/in³) | | **Melting Range** | 1410 - 1440°C (2570 - 2625°F) | | **Thermal Conductivity** | 19 - 20 W/m·K | | **Coefficient of Thermal Expansion** | 10.5 x 10⁻⁶ /°C (20-100°C) | | **Specific Heat** | 460 J/kg·K | | **Electrical Resistivity** | 0.60 - 0.65 μΩ·m | | **Magnetic Properties** | Ferromagnetic (Martensitic) | --- ### **Key Characteristics & Advantages** * **Unmatched Strength-Toughness Synergy:** Provides the best overall balance of ultra-high strength and fracture toughness in its class. * **Excellent Fabricability (Annealed State):** Can be easily machined, formed, and welded in the solution-annealed condition (~30 HRC). * **Simple, Low-Distortion Aging:** The final aging process requires no quenching, minimizes distortion, and allows for precise dimensional control. * **Superior Damage Tolerance:** High fracture toughness enables damage-tolerant design principles, providing a safety margin against unforeseen flaws. * **Good Stress Corrosion Cracking (SCC) Resistance:** Inherently more resistant to SCC than many other ultra-high-strength steels. * **Proven Reliability:** Extensive history in critical aerospace applications with well-documented performance. --- ### **International Standards & Designations** This is one of the most standardized and widely specified ultra-high-strength steels. | Standard/System | Designation | Title / Notes | |----------------|-------------|---------------| | **Aerospace Material Spec (AMS)** | **AMS 6521** | *Steel Bars, Forgings, and Tubing 18.5Ni-9.0Co-4.9Mo-0.65Ti (Maraging 300)*. This is the **primary governing specification**. The "300" denotes 300 ksi UTS. | | **ASTM International** | **ASTM A538 Grade B** | *Precipitation-Hardening Alloy Steel Bar, Forging, and Forging Stock for High-Strength Service.* Commonly references this strength level. | | **Proprietary/Trade Name** | **ATI Allvac VascoMax C-300**, **Marval M18-300** | Leading commercial names. | | **Unified Numbering System (UNS)** | **K92890** | Standard designation for 18Ni maraging steels. | | **Military Standard** | **MIL-S-46850** | Covers maraging steels including this grade. | | **European** | **X2NiCoMo18-9-5** (similar) | Rough equivalent in material designation system. | --- ### **Primary Applications** VascoMax C-300 is the **benchmark material** for critical, weight-sensitive structural components across advanced industries. 1. **Aerospace & Defense (Primary Use):** * **Rocket and Missile Motor Casings:** For space launch vehicles, ICBMs, and tactical missiles. * **Aircraft Landing Gear:** Critical forgings for main struts, trucks, and pistons in fighter jets, commercial aircraft, and UAVs. * **Helicopter Rotor Hubs, Flexbeams, and Drive Shafts.** * **Satellite and Spacecraft Structures:** Booms, fittings, deployment mechanisms, and fuel tanks. 2. **Tooling & High-Pressure Equipment:** * **Extrusion Dies and Mandrels** for titanium and nickel superalloys. * **Die Inserts for High-Pressure Die Casting.** * **Components for Isostatic Pressing (HIP) Tooling.** * **Precision Shafts and Spindles** in high-load machinery. 3. **High-Performance Automotive & Racing:** * **Formula 1 and Top-Fuel Connecting Rods, Gears, and Suspension Components.** * **High-Strength Fasteners** for safety-critical assemblies. --- ### **Fabrication & Processing Guidelines** * **Machining:** Perform all heavy machining in the **solution-annealed** condition. Machining aged material is difficult; use CBN or premium carbide tooling with high-pressure coolant. * **Forming:** All significant forming must be done in the annealed state. * **Welding:** Use GTAW (TIG) with a **matching filler metal** (e.g., ER18Ni). **Post-Weld Heat Treatment (PWHT)** is **mandatory** for critical applications: full re-solution anneal (927°C) followed by aging. * **Heat Treatment:** Precise temperature control (±5°C) during aging is critical for consistent properties. * **Corrosion Protection:** **Not stainless.** Requires protective coatings: **electroless nickel, cadmium-titanium plating, or specialized paint systems.** **Post-plate baking** is essential to prevent hydrogen embrittlement. --- ### **Comparison with Other Grades** | Feature | VascoMax C-300 (300 ksi UTS) | VascoMax C-250 (250 ksi UTS) | 4340M (260-280 ksi UTS) | |---------|-------------------------------|-------------------------------|-------------------------| | **Strengthening** | Precipitation (Intermetallic) | Precipitation (Intermetallic) | Quench & Temper (Carbides) | | **Typical YS** | ~1960-2050 MPa | ~1725-1790 MPa | ~1790-1930 MPa | | **Toughness (KIC)** | **Excellent (75-90 MPa√m)** | **Very Good (55-75 MPa√m)** | Moderate (50-65 MPa√m) | | **Aging Distortion** | Very Low | Very Low | High (Quench Cracks/Distortion) | | **Weldability** | Good (with PWHT) | Good (with PWHT) | Poor | | **Key Advantage** | **Best Overall Balance** | **Higher Toughness at 250 ksi** | **Lower Cost** | --- ### **Summary** **ATI Allvac® VascoMax® C-300**, processed via the industry-standard **927°C (1700°F) austenitize and 482°C (900°F) age** cycle, is the **definitive ultra-high-strength maraging steel**. It delivers an unparalleled and proven combination of **extreme strength, exceptional toughness, and reliable manufacturability**. Its status as the material of record in countless aerospace and defense standards (like AMS 6521) underscores its reliability and performance. For engineers designing structures where failure is not an option and every gram of mass is critical, C-300 remains the **first and most trusted choice**, successfully bridging the gap between theoretical material limits and practical, mission-critical engineering reality. -:- For detailed product information, please contact sales. -: ATI Allvac® VascoMax® C-300 Specialty Steel, Heat Treatment: 927°C (1700°F) + Age Specification Dimensions Size： Diameter 20-1000 mm Length <7362 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ATI Allvac® VascoMax® C-300 Specialty Steel, Heat Treatment: 927°C (1700°F) + Age Properties -:- For detailed product information, please contact sales. -:

Applications of ATI Allvac® VascoMax® C-300 Specialty Steel Wire, Heat Treatment: 927°C (1700°F) + Age -:- For detailed product information, please contact sales. -: Chemical Identifiers ATI Allvac® VascoMax® C-300 Specialty Steel Wire, Heat Treatment: 927°C (1700°F) + Age -:- For detailed product information, please contact sales. -:

Packing of ATI Allvac® VascoMax® C-300 Specialty Steel Wire, Heat Treatment: 927°C (1700°F) + Age -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Wire 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 3833 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition