Maraging 250,Udimar 250 Rod,,E FORU

British Specs:BS S162，American Specs:AMS 6512 Bar, Tube, Forgings AMS 6520 Sheet, Strip and Plate ASTM A646 MIL-S-46850 Type 3，German Specs:WS 1.6359

### **Product Datasheet: Maraging Steel 250 / Udimar 250 Rod** --- #### **1. Product Overview** **Maraging Steel 250 Rod** (commercially known as **Udimar 250 Rod**) is a premium-grade round bar product manufactured from ultra-high-strength maraging steel. This martensitic age-hardening steel rod offers an exceptional combination of high tensile strength, excellent fracture toughness, and superior dimensional stability during heat treatment. The rod form provides ideal stock material for machining critical components where maximum reliability and precision are required in aerospace, defense, and tooling applications. --- #### **2. Chemical Composition (Weight %)** | Element | Min (%) | Max (%) | Balance | |---------|----------|----------|---------| | **Nickel (Ni)** | 17.00 | 19.00 | - | | **Cobalt (Co)** | 7.00 | 8.50 | - | | **Molybdenum (Mo)** | 4.50 | 5.20 | - | | **Titanium (Ti)** | 0.30 | 0.50 | - | | **Aluminum (Al)** | 0.05 | 0.15 | - | | **Iron (Fe)** | - | - | Balance | | **Carbon (C)** | - | 0.03 | - | | **Manganese (Mn)** | - | 0.10 | - | | **Silicon (Si)** | - | 0.10 | - | | **Sulfur (S)** | - | 0.01 | - | | **Phosphorus (P)** | - | 0.01 | - | --- #### **3. Physical & Mechanical Properties** **A. Mechanical Properties (After Solution Annealing & Aging)** - **Tensile Strength:** 1,720 - 1,790 MPa (250 - 260 ksi) - **Yield Strength (0.2% Offset):** 1,655 - 1,725 MPa (240 - 250 ksi) - **Elongation:** 10 - 14% - **Reduction in Area:** 45 - 55% - **Hardness:** 48 - 52 HRC - **Fracture Toughness (K_Ic):** 70 - 90 MPa√m - **Impact Toughness (Charpy V):** 25 - 35 J **B. Physical Properties** - **Density:** 8.00 g/cm³ (0.289 lb/in³) - **Modulus of Elasticity:** 185 GPa (26.8 × 10⁶ psi) - **Poisson's Ratio:** 0.30 - **Thermal Conductivity:** 19.0 - 21.0 W/m·K - **Thermal Expansion Coefficient:** 10.5 - 11.0 × 10⁻⁶/°C (20 - 100°C) - **Electrical Resistivity:** 0.60 - 0.65 μΩ·m **C. Rod Specifications** - **Diameter Range:** 5 mm - 300 mm (0.2" - 12") - **Standard Lengths:** 3,000 mm & 4,000 mm (10' & 13') - **Diameter Tolerance:** h11 for standard precision - **Straightness:** ≤ 1.5 mm/m - **Surface Finish:** Turned, ground, or polished available --- #### **4. Product Applications** **Aerospace & Defense** - **Rocket motor case** segments and closures - **Aircraft landing gear** components and actuators - **Missile body** sections and structural members - **Helicopter rotor** shafts and drive systems - **Ordnance components** and gun barrels **Tooling & Manufacturing** - **Precision mold** bases and cavity inserts - **Die-casting** cores and ejector pins - **Extrusion press** rams and stems - **Injection molding** machine screws and barrels - **Fixture** components and jig details **High-Performance Industrial** - **Racing engine** components and connecting rods - **High-strength fasteners** and special bolts - **Hydraulic cylinder** rods and pistons - **Test equipment** shafts and load cells - **Optical mounting** systems and instrument frames --- #### **5. International Standards & Specifications** | Standard Body | Specification Number | Title/Description | |---------------|----------------------|-------------------| | **AMS** | AMS 6512 | Steel Bars, Forgings, and Tubing 18Ni (250) | | **ASTM** | A538 | Standard Specification for Precipitation-Hardening Steel | | **UNS** | K92890 | Unified Numbering System Designation | | **MIL** | MIL-S-46850 | Steel, Maraging 250 Grade | | **ISO** | 683-13 | Heat-treatable steels, alloy steels, and free-cutting steels | | **DIN** | 1.6358 | Material designation for X2NiCoMo18-8-5 | --- #### **6. Heat Treatment Process** **Solution Annealing (Recommended before machining)** - **Temperature:** 820 ± 10°C (1,508 ± 18°F) - **Time:** 1 hour per 25 mm of diameter - **Atmosphere:** Protective atmosphere recommended - **Cooling:** Air cool to room temperature **Aging Treatment (After machining)** - **Temperature:** 480 ± 5°C (896 ± 9°F) - **Time:** 3 hours minimum (up to 6 hours for heavy sections) - **Cooling:** Air cool to room temperature **Heat Treatment Advantages for Rod Products:** - Minimal distortion and dimensional changes - Uniform properties throughout cross-section - No quenching stresses or cracking risk - Excellent surface condition maintained --- #### **7. Machining & Fabrication Guidelines** **Machining in Annealed Condition** - **Hardness:** 28-32 HRC (ideal for machining) - **Tooling:** Carbide tools recommended for production - **Speeds:** Moderate to high speeds with positive rake angles - **Coolant:** Required for heavy cuts and threading operations **Finishing Operations after Aging** - **Grinding:** Suitable for final dimensional adjustment - **EDM:** Excellent results for complex geometries - **Polishing:** Achieves mirror finishes when required - **Coating:** Various surface treatments compatible --- #### **8. Quality Assurance** **Standard Testing & Certification** - **Chemical Analysis:** Certified ladle and product analysis - **Mechanical Testing:** Tensile and impact tests from representative samples - **Ultrasonic Testing:** Available for critical applications - **Macroetch Testing:** Assess internal soundness - **Certification:** EN 10204 3.1/3.2 material certificates **Additional Quality Features** - **Traceability:** Full melt history and processing records - **Surface Quality:** Free from seams and harmful defects - **Dimensional Control:** Certified to specified tolerances - **Batch Consistency:** Maintained through statistical process control --- **Packaging & Handling:** - Protective end caps to prevent damage - Individual wrapping or wooden crating - Clear identification and heat number marking - Custom cutting services available **Contact Information:** [Your Company Information] *Note: All mechanical properties are typical for material in the fully aged condition. Properties may vary based on specific diameter and heat treatment parameters. Consult our technical team for application-specific recommendations.*

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 2574 gallon liquid totes Special package is available on request.