Maraging 250,Udimar 250 Pipe,,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 Pipe** --- #### **1. Product Overview** **Maraging Steel 250 Pipe** (commercially known as **Udimar 250 Pipe**) is a seamless tubular product manufactured from ultra-high-strength maraging steel, designed for applications requiring exceptional strength-to-weight ratio in hollow sections. This martensitic age-hardening steel pipe combines the superior mechanical properties of Maraging 250 with the advantages of tubular construction, providing optimal solutions for pressure vessels, structural components, and high-performance systems in aerospace, defense, and energy industries. The pipe form offers excellent pressure containment capability while minimizing weight. --- #### **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 - **Burst Pressure Ratio:** Excellent performance under internal pressure **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. Pipe Specifications** - **Outside Diameter Range:** 12 mm - 250 mm (0.5" - 10") - **Wall Thickness:** 2 mm - 25 mm (0.08" - 1.0") - **Length:** 3,000 mm - 6,000 mm (10' - 20') - **Diameter Tolerance:** ±0.5% of nominal OD - **Wall Thickness Tolerance:** ±10% of nominal wall - **Straightness:** ≤ 1.0 mm/m --- #### **4. Product Applications** **Aerospace & Defense** - **Rocket motor cases** and launch tube structures - **Aircraft hydraulic** system components - **Missile body sections** and structural tubes - **Helicopter rotor** shafts and drive systems - **Ordnance components** and pressure vessels **Energy & Industrial** - **High-pressure gas** storage cylinders - **Hydraulic accumulator** shells - **Process industry** high-pressure tubing - **Oil and gas** downhole tools - **Nuclear reactor** components **High-Performance Applications** - **Racing vehicle** roll cages and structural tubes - **High-pressure test** equipment fixtures - **Marine applications** requiring corrosion resistance - **Special vehicle** frame components - **Scientific instrument** vacuum chambers --- #### **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 | | **ASTM** | A789 | Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing | | **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 | --- #### **6. Heat Treatment Process** **Solution Annealing (Recommended before forming)** - **Temperature:** 820 ± 10°C (1,508 ± 18°F) - **Time:** 1 hour per 25 mm of wall thickness - **Atmosphere:** Protective atmosphere required - **Cooling:** Air cool to room temperature **Aging Treatment (After final machining/forming)** - **Temperature:** 480 ± 5°C (896 ± 9°F) - **Time:** 3-5 hours depending on wall thickness - **Cooling:** Air cool to room temperature **Special Considerations for Pipe:** - Uniform heating during heat treatment critical - Support required to prevent sagging during processing - Internal surface protection recommended --- #### **7. Fabrication & Welding** **Machining & Forming:** - **Optimal Condition:** Machine in solution-annealed state - **Tooling:** Carbide tools recommended - **Bending:** Minimum bend radius 3x pipe diameter - **Threading:** Excellent results with proper tooling **Welding Procedures:** - **Weldability:** Good with proper techniques - **Processes:** TIG welding preferred for critical applications - **Filler Metal:** Matching composition recommended - **Pre/Post Heat Treatment:** Solution anneal after welding, age after all fabrication --- #### **8. Quality Assurance** **Standard Testing:** - **Hydrostatic Testing:** To required pressure levels - **Ultrasonic Testing:** 100% wall thickness verification - **Dimensional Inspection:** OD, wall thickness, and straightness - **Surface Quality:** Internal and external surface examination **Additional Quality Features:** - **Full Traceability:** From melt to finished pipe - **Certification:** EN 10204 3.1/3.2 material certificates - **NDT Capability:** Ultrasonic, dye penetrant, radiographic - **Pressure Rating Certification:** When required --- **Packaging & Handling:** - Protective end caps to prevent damage - Individual wrapping or wooden crating - Clear identification and heat number marking - Special handling for large diameters **Contact Information:** [Your Company Information] *Note: All mechanical properties are typical for material in the fully aged condition. Pressure ratings and performance characteristics should be verified for specific applications. Consult our engineering team for design and fabrication 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 2576 gallon liquid totes Special package is available on request.