Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel

Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel Product Information -:- For detailed product information, please contact sales. -: Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel Synonyms -:- For detailed product information, please contact sales. -:

Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel Product Information -:- For detailed product information, please contact sales. -: # Latrobe Marvac 250 VIM-VAR ## Premium High-Strength Maraging Steel - 5 Inch Cross-Section --- ### **Product Overview** **Latrobe Marvac 250 VIM-VAR** is a **premium-grade, vacuum-remelted maraging steel** supplied in a **5-inch (127 mm) cross-section**. Produced via the **Vacuum Induction Melting (VIM) followed by Vacuum Arc Remelting (VAR)** double-melt process, this material represents the optimal balance of **superior quality, manageable size, and cost-effectiveness** for critical aerospace, defense, and tooling applications. The **250 designation** denotes its nominal yield strength of **250 ksi (≈1725 MPa)** after standard precipitation hardening. The 5-inch diameter is a versatile "sweet spot" - large enough for substantial structural components while still ensuring excellent through-hardening and property uniformity with the VIM-VAR process. --- ### **Chemical Composition (Weight %)** *Precisely controlled for optimal hardenability and toughness in the 5-inch range.* | Element | Specification Range | Typical VIM-VAR Analysis (5") | Critical Function for 5" Section | |---------|-------------------|------------------------------|----------------------------------| | **Nickel (Ni)** | 17.5 - 19.0 | 18.5 | Ensures complete martensitic transformation. Slightly elevated vs. air-melt for core guarantee. | | **Cobalt (Co)** | 7.5 - 8.5 | 8.0 | Drives precipitation; optimized for cost/performance in this section size. | | **Molybdenum (Mo)** | 4.5 - 5.2 | 4.9 | Primary hardener; VIM ensures uniform distribution. | | **Titanium (Ti)** | 0.3 - 0.5 | 0.4 | Secondary hardener; controlled to minimize large TiN inclusions. | | **Aluminum (Al)** | 0.05 - 0.15 | 0.10 | Deoxidizer. | | **Carbon (C)** | ≤ 0.03 | 0.01 | Ultra-low for maximum toughness. | | **Manganese (Mn)** | ≤ 0.10 | 0.05 | Minimized to prevent banding. | | **Silicon (Si)** | ≤ 0.10 | 0.05 | Controlled. | | **Boron (B)** | 0.003 - 0.006 | 0.004 | Enhances hardenability for full 5" transformation. | | **Zirconium (Zr)** | 0.01 - 0.03 | 0.02 | Grain refiner for forged microstructure. | | **Sulfur (S)** | ≤ 0.005 | 0.002 | **Extra-Low Sulfur (ELS).** Critical for transverse properties. | | **Phosphorus (P)** | ≤ 0.008 | 0.003 | Tightly controlled. | | **Iron (Fe)** | Balance | Balance | Base. | **Melting Practice (VIM-VAR) Rationale for 5" Section:** While air-melted product may suffice for some 5" applications, VIM-VAR is specified to guarantee: 1. **Elimination of Macro-Segregation:** Critical for consistent core properties. 2. **Superior Microcleanliness:** Essential for high-cycle fatigue performance in dynamic components. 3. **Predictable Property Gradient:** Minimal strength drop from surface to center (< 2%). 4. **Compliance with Aerospace Specifications:** Most critical aerospace components in this size range mandate premium melting. --- ### **Heat Treatment for 5-Inch Sections** 1. **Solution Annealing:** * **Temperature:** 820°C ± 10°C (1508°F) * **Time:** **4-6 hours** (sufficient for thermal penetration) * **Cooling:** **Air Cool** is typically sufficient, ensuring minimal residual stress and low distortion. 2. **Aging (Precipitation Hardening):** * **Temperature:** 480°C ± 5°C (896°F) * **Time:** **6-8 hours** (ensures full aging to center) * **Cooling:** Air Cool. --- ### **Mechanical Properties (Aged Condition - 5" Section)** *Guaranteed minimums from test locations at **Surface (S), 1/2 Radius (R/2), and Center (C)**.* | Property | Location | Minimum Guaranteed | Typical Achieved (5" VIM-VAR) | Test Standard | |----------|----------|-------------------|------------------------------|---------------| | **0.2% Yield Strength** | **Center (C)** | **1680 MPa (244 ksi)** | **1700 - 1760 MPa** | ASTM E8 | | **0.2% Yield Strength** | Surface (S) | 1710 MPa (248 ksi) | 1730 - 1790 MPa | ASTM E8 | | **Ultimate Tensile Strength** | Center (C) | 1730 MPa (251 ksi) | 1750 - 1820 MPa | ASTM E8 | | **Elongation (in 4D)** | Center (C) | 10% | 11 - 14% | ASTM E8 | | **Reduction of Area** | Center (C) | 40% | 45 - 55% | ASTM E8 | | **Hardness** | All Locations | 48 HRC | 49 - 52 HRC | ASTM E18 | | **Fracture Toughness (K_IC)** | R/2 (L-T) | **85 MPa√m** | **90 - 115 MPa√m** | ASTM E399 | | **Impact Energy (Charpy V)** | Center (L) | 30 J | 35 - 50 J | ASTM E23 | **Property Uniformity Advantage (5" VIM-VAR vs. Air-Melt):** * **Core Strength Consistency:** VIM-VAR ensures center yield strength is ≥ 99% of surface strength. * **Transverse Ductility:** Dramatically improved due to low sulfur and spherical inclusions. * **Fatigue Life:** Can be 2-3x higher than air-melted material due to superior cleanliness. --- ### **Physical Properties (Aged)** | Property | Value | |----------|-------| | **Density** | 8.00 - 8.02 g/cm³ | | **Thermal Conductivity** | 20 - 22 W/(m·K) | | **Coefficient of Thermal Expansion** | 10.8 x 10⁻⁶ /K (20-100°C) | | **Modulus of Elasticity** | 185 - 190 GPa | | **Magnetic Properties** | Ferromagnetic | --- ### **Key Advantages of 5" VIM-VAR Product** 1. **Optimal Size for Many Critical Components:** Ideal for aircraft landing gear struts, helicopter rotor shafts, large fasteners, and extrusion rams. 2. **Excellent Hardenability with Air Cooling:** Eliminates quench cracking risk associated with oil quenching larger sections. 3. **Superior Machinability Predictability:** Homogeneous structure allows for consistent machining rates and tool life throughout the cross-section. 4. **Cost-Effective Premium Quality:** While more expensive than air-melt, the 5" size avoids the extreme cost and lead time of very large (10"+) VIM-VAR ingots, while delivering nearly all the quality benefits. --- ### **International Standards & Certifications** * **Primary Specifications:** * **AMS 6521** (Baseline for 18Ni maraging steel) * **AMS 6512** (May be invoked for specific 10Ni-8Co compositions) * **Cleanliness Standards:** Typically supplied to **AMS 2301** (Premium Aircraft-Quality Steel Cleanliness) or **AMS 2300**. * **Customer Approvals:** Commonly procured against **Boeing BMS 7-348**, **Airbus AITM**, and **Pratt & Whitney** material specifications that require VIM-VAR for rotating or fracture-critical parts. * **Certification:** **EN 10204 3.2 Certificate** with full traceability (VIM heat #, VAR ingot #, forge lot, heat treat lot). Includes full ultrasonic test report. --- ### **Primary Applications** The 5" VIM-VAR product is the workhorse for high-integrity components in medium to large sizes. 1. **Aerospace:** * **Landing Gear Components:** Struts, pistons, torque links for regional jets, business jets, and narrow-body aircraft. * **Helicopter Dynamic Components:** Rotor mast sections, drive shafts, pitch links. * **Engine Mounts and Pylons.** * **Critical Airframe Fittings and Lugs.** 2. **Defense:** * **Gun Barrel Components** (breech rings, recoil cylinders). * **Missile Launch Rail Components.** * **Armor Vehicle Suspension Components.** 3. **Tooling & Industrial:** * **Extrusion Rams and Mandrels** for aluminum and titanium. * **Die Blocks for Precision Forging.** * **Components for High-Pressure Isostatic Presses (HIP).** 4. **Energy:** * **High-Strength Shafts** for pumps and compressors. * **Valve Stems and Components** for high-pressure service. --- ### **Fabrication & Quality Assurance** **Forging & Processing:** * The 5" cross-section is typically produced from a larger VAR ingot via cogging or forging to refine the grain structure. * **Ultrasonic Testing:** **100% volumetric UT** performed from circumferential and end directions to **ASTM A388** standards, often to **Quality Level 3 (QL3)** or better (e.g., FBH 1.2 mm). * **Macroetch:** Required to confirm sound center and proper grain flow. **Machining & Heat Treatment:** * Most machining is performed in the **solution-annealed condition** (~30 HRC). * Heat treatment furnaces must have proven uniformity; for 5" sections, standard industrial furnaces are usually adequate. --- ### **Economic & Procurement Profile** * **Lead Time:** Shorter than 10"+ sections, typically **4-8 months** from order to delivery. * **Cost:** Premium over air-melt but represents the best value-for-money in the VIM-VAR range. * **Availability:** More readily available than larger VIM-VAR sizes due to more frequent production cycles. --- ### **Comparison: 5" VIM-VAR vs. 5" Air-Melt** | Characteristic | **5" VIM-VAR** | **5" Air-Melt** | |----------------|----------------|-----------------| | **Center Segregation** | **Negligible** | Possible (Mn, P, S) | | **Inclusion Content** | **Very Low (AMS 2301)** | Higher (AMS 2300 or commercial) | | **Transverse Ductility** | **Excellent** | Good to Fair | | **Fatigue Performance** | **Superior** | Standard | | **Property Gradient** | **< 2%** | 3-5% | | **Cost** | **High** | Moderate | | **Typical Application** | **Fracture-Critical, Rotating Parts** | Static Structural, Tooling | --- ### **Summary** **Latrobe Marvac 250 VIM-VAR in 5-inch cross-section** is the **premium default choice** for engineers designing critical, load-bearing components that are too large for conventional hardening consistency but do not require the massive 10"+ billet size. It delivers **95% of the quality benefits of VIM-VAR melting** at a **more accessible size and cost point**. This product is specified when the application demands **guaranteed core properties, superior fatigue life, and maximum reliability** - typically for aerospace flight-critical parts, high-performance defense systems, and severe-service industrial tooling. The 5-inch diameter represents the practical intersection of **uncompromising material quality** and **manufacturing efficiency**, making it one of the most versatile and widely used premium maraging steel product forms in the industry. -:- For detailed product information, please contact sales. -: Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel Specification Dimensions Size： Diameter 20-1000 mm Length <7376 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. -: Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel -:- For detailed product information, please contact sales. -:

Packing of Latrobe Marvac 250 VIM-VAR ; 5 in. High Strength Maraging Steel -:- 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 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 3847 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