AISI Grade 18Ni (250) Maraging Steel, solution annealed

AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours Product Information -:- For detailed product information, please contact sales. -: AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours Synonyms -:- For detailed product information, please contact sales. -:

AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours Product Information -:- For detailed product information, please contact sales. -: ### **Product Data Sheet: AISI 18Ni (250) Maraging Steel Sheet** **Specified Condition:** 3.18 mm thick sheet, Solution Annealed at 815°C (1500°F) for 30 minutes, Air Cooled, then Aged at 455°C (850°F) for 3 hours. **Product Overview** This datasheet describes **AISI 18Ni (250) Maraging Steel** supplied as a **3.18 mm (0.125") thick sheet** that has undergone a complete and specified two-stage heat treatment cycle: solution annealing followed by a lower-temperature aging process. This specific aging parameter (455°C / 850°F) is often selected to optimize the balance between ultimate strength and fracture toughness or stress corrosion cracking resistance for thin-section components. The material is delivered in its final, ready-to-use aged condition, exhibiting the characteristic ultra-high strength, excellent dimensional stability, and good ductility of the Grade 250 class. **Material & Specified Heat Treatment** * **Grade:** 18% Nickel Maraging Steel, Grade 250 (Nominal Yield Strength: 250 ksi / 1725 MPa). * **Product Form:** Cold-rolled or hot-rolled **Sheet**, 3.18 mm (0.125") nominal thickness. * **Final Condition:** **Peak Aged via Modified Parameters.** The sheet has been processed per the exact customer specification: 1. **Solution Anneal:** **815°C (1500°F) for 30 minutes**, Air Cooled. This time is sufficient for full austenitization and homogenization of the thin section, resulting in a soft, low-carbon martensitic structure ideal for subsequent forming or machining. 2. **Age Hardening:** **455°C (850°F) for 3 hours**, Air Cooled. Aging at this slightly lower temperature (vs. the standard 480°C/900°F) typically results in: * A marginal reduction in peak yield strength (by approximately 3-7%). * A potentially significant improvement in fracture toughness (K_IC) and resistance to stress corrosion cracking (SCC). * Excellent property uniformity through the thin section. **Chemical Composition (Typical Weight %, per AMS 6514)** | Element | Content (%) | Element | Content (%) | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | 17.0 - 19.0 | **Cobalt (Co)** | 7.0 - 8.5 | | **Molybdenum (Mo)**| 4.6 - 5.2 | **Titanium (Ti)** | 0.3 - 0.5 | | **Aluminum (Al)** | 0.05 - 0.15 | **Carbon (C)** | **≤ 0.03 max** | | **Manganese (Mn)**| ≤ 0.10 max | **Silicon (Si)** | ≤ 0.10 max | | **Sulfur (S)** | ≤ 0.010 max | **Phosphorus (P)** | ≤ 0.010 max | | **Boron (B)** | 0.003 (min) | **Zirconium (Zr)**| 0.01 - 0.02 | | **Calcium (Ca)** | 0.05 (max) | **Iron (Fe)** | Balance | **Physical & Mechanical Properties (After Specified Aging: 455°C/3hrs)** * **Density:** 8.0 g/cm³ (0.289 lb/in³) * **Melting Point:** ~ 1415°C (2580°F) * **Mechanical Properties (Typical for 3.18mm sheet, longitudinal):** * **Ultimate Tensile Strength (UTS):** **1670 - 1740 MPa (242 - 252 ksi)** * **Yield Strength (0.2% Offset):** **1640 - 1710 MPa (238 - 248 ksi)** * **Elongation (% in 50mm):** **10 - 14%** * **Hardness:** **46 - 50 HRC** * **Fracture Toughness (K_Ic):** **Very High, typically 90 - 120 MPa√m** (Benefit of lower-temperature aging). * **Modulus of Elasticity:** 185 GPa (27 x 10⁶ psi) * **Thermal Properties (at ~20°C):** * **Thermal Expansion Coefficient:** 10.2 x 10⁻⁶/K * **Thermal Conductivity:** ~ 20.0 W/m·K * **Key Characteristics of this Treatment:** * **Toughness-Optimized:** The primary rationale for the 455°C aging cycle is to maximize damage tolerance and resistance to crack propagation in thin, highly stressed structures. * **Uniform Properties:** The thin gauge ensures rapid and uniform heat treatment, minimizing gradients. **Key Characteristics & Advantages** 1. **Optimized Toughness-Strength Balance:** This specific aging treatment deliberately trades a small amount of peak strength for a substantial gain in fracture toughness, making it ideal for fatigue-critical and damage-tolerant designs. 2. **Minimal Distortion & High Stability:** The entire heat treatment (air cooling from both solution and aging temperatures) ensures exceptionally low residual stress and dimensional change, critical for precision sheet components. 3. **Ready for Use:** Supplied in the final aged condition, requiring no further heat treatment by the user. 4. **Excellent Machinability (in Annealed State):** Any required cutting or forming must be completed on material in the solution-annealed condition prior to this final aging. **Primary Applications** This specific product and heat treatment are chosen for demanding, thin-section applications where crack resistance is as important as pure strength: * **Aerospace & Defense:** Thin-walled pressure vessels, missile and rocket motor cases, helicopter rotor blades spars, lightweight armor plating components. * **High-Performance Sporting Equipment:** Critical components in professional cycling frames, aerospace-derived bicycles, and high-stress parts in racing sailboats. * **Precision Instruments & Optics:** Stable mounting plates and structural frames for sensitive measurement equipment where dimensional stability under load is critical. * **Medical Devices:** Components for surgical tools or imaging systems requiring high strength, non-magnetic properties, and reliability. * **Test Coupons & Prototypes:** For material characterization and design validation under toughness-driven criteria. **International & Industry Standards** * **AMS 6521:** *Aerospace Material Specification for Maraging Steel Bars, Forgings, and Rings...* (The primary governing spec for aged material; properties will be noted as non-standard due to the aging temperature). * **AMS 6514:** Specifies the solution-annealed condition prior to aging. * **ASTM A579 / A579M:** A key reference specification for the 18Ni (250) grade. * **Customer-Specific Heat Treat Specification:** This product is explicitly made to a customer-defined aging parameter (455°C/3hrs). Certification will reference this specific work order/requirement. * **UNS K92890:** Unified Numbering System designation. * **ISO 683-13:** International standard covering wrought maraging steels. **Disclaimer:** This material has been aged to parameters that differ from the standard industry peak-aging temperature. The mechanical properties reflect this specific **toughness-optimized** condition and are not directly comparable to those from a 480°C (900°F) aging cycle. The material is in its final heat-treated state and is **not weldable or formable**. Any post-delivery processing that involves heating above approximately 300°C (570°F) will alter the metallurgical structure and degrade properties. All application engineering must be based on the certified test report from the supplier for this specific lot and heat treatment. -:- For detailed product information, please contact sales. -: AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours Specification Dimensions Size： Diameter 20-1000 mm Length <7326 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. -: AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours -:- For detailed product information, please contact sales. -:

Packing of AISI Grade 18Ni (250) Maraging Steel, 3.18 mm thick sheet, solution annealed at 815°C (1500°F) for 30 minutes, air cooled, aged at 455°C (850°F) for 3 hours -:- 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 3797 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