AISI Grade 18Ni (300) Maraging Steel nominal annealed

AISI Grade 18Ni (300) Maraging Steel nominal annealed properties Product Information -:- For detailed product information, please contact sales. -: AISI Grade 18Ni (300) Maraging Steel nominal annealed properties Synonyms -:- For detailed product information, please contact sales. -:

AISI Grade 18Ni (300) Maraging Steel nominal annealed properties Product Information -:- For detailed product information, please contact sales. -: # AISI Grade 18Ni (300) Maraging Steel - Nominal Annealed Properties ## Overview AISI Grade 18Ni (300) Maraging Steel in the **nominal annealed condition** (typically solution annealed at 815°C/1500°F for 1 hour, air cooled) provides a soft, ductile, and machinable state suitable for fabrication before final age hardening. This intermediate condition features a low-carbon martensitic structure with minimal hardness, enabling extensive machining, forming, and welding operations with dimensional stability. The annealed material serves as the essential precursor state that will later develop ultra-high strength (2000+ MPa) through precipitation hardening. --- ## Chemical Composition (Weight %) | Element | Content (%) | Element | Content (%) | |--------------|-------------|------------|-------------| | Nickel (Ni) | 18.00–19.00 | Cobalt (Co)| 8.50–9.50 | | Molybdenum (Mo)| 4.60–5.20 | Titanium (Ti)| 0.55–0.80 | | Aluminum (Al)| 0.05–0.15 | Carbon (C) | ≤0.030 | | Manganese (Mn)| ≤0.10 | Silicon (Si)| ≤0.10 | | Sulfur (S) | ≤0.010 | Phosphorus (P)| ≤0.010 | | Boron (B) | 0.003–0.005| Zirconium (Zr)| 0.01–0.02 | | Iron (Fe) | Balance | | | *Note: Composition is identical to aged material; trace elements may be adjusted for improved machinability in annealed state.* --- ## Heat Treatment Specification (Nominal Annealed Condition) - **Process**: Solution Annealing - **Temperature**: 815°C (1500°F) ± 10°C - **Time**: 1 hour per inch of thickness (minimum 1 hour) - **Cooling**: Air cool or faster - **Resulting Structure**: Soft, low-carbon martensite with minimal residual austenite - **Purpose**: Produces uniform, workable material for fabrication; dissolves precipitates from previous processing --- ## Physical & Mechanical Properties (Annealed Condition) | Property | Value | |-----------------------------------|--------------------------------------------------------------------| | **Ultimate Tensile Strength (UTS)** | 1000–1100 MPa (145–160 ksi) | | **Yield Strength (0.2% Offset)** | 950–1050 MPa (138–152 ksi) | | **Elongation (% in 50 mm)** | 14–18% | | **Reduction in Area** | 65–75% | | **Hardness** | 28–32 HRC (typical: 30 HRC) | | **Modulus of Elasticity** | 180–185 GPa (26–27 × 10⁶ psi) | | **Poisson's Ratio** | 0.30–0.32 | | **Density** | 8.0 g/cm³ (0.289 lb/in³) | | **Electrical Resistivity** | 0.60–0.65 μΩ·m at 20°C | | **Thermal Conductivity (20°C)** | 20–22 W/m·K | | **Coefficient of Thermal Expansion** | 10.5 × 10⁻⁶/°C (20–100°C) | | **Magnetic Properties** | Ferromagnetic (martensitic structure) | --- ## Key Characteristics in Annealed Condition - **Excellent Machinability**: Comparable to alloy steels of similar hardness; significantly better than in aged condition. - **Formability**: Can be cold formed with moderate deformation; hot forming possible at 700–925°C (1290–1700°F). - **Weldability**: Excellent in annealed state; all conventional welding methods applicable without preheat. - **Dimensional Stability**: Minimal distortion during subsequent aging (typically <0.0005 in/in). - **Uniform Structure**: Homogeneous microstructure ensures consistent properties throughout section. - **Stress Relief**: Annealing eliminates residual stresses from prior processing. --- ## Fabrication Advantages - **Machining**: 20–30% faster machining rates compared to aged condition; reduced tool wear. - **Welding**: No preheat required; post-weld heat treatment (re-annealing or aging) restores properties. - **Forming**: Can be bent, punched, or shaped with standard tooling. - **Finish Machining**: Near-net-shape components can be machined to final dimensions before aging. - **Inspection**: Non-destructive testing (UT, RT) more effective in softer condition. --- ## International Standards & Designations (Annealed Condition) | Standard | Designation | Condition Specification | |-------------------|---------------------------------------|------------------------------------------| | **ASTM (USA)** | ASTM A538 Grade B | Annealed or solution treated | | **AMS (Aerospace)**| AMS 6521C | Solution treated at 815°C (1500°F) | | **AMS (Aerospace)**| AMS 6514D | Annealed condition | | **UNS** | K92890 | 18Ni (300) Maraging Steel | | **ISO** | ISO 683-13:2016 | X2NiCoMo 18-9-5 (annealed) | | **MIL-S** | MIL-S-46850 | Solution annealed condition | | **Proprietary** | VascoMax 300, Marval 18, etc. | Typically supplied annealed | *Note: Material certifications for annealed condition should specify "solution annealed" per applicable standard.* --- ## Typical Applications for Annealed Material - **Precision Tooling Components**: Mold bases, die blocks, and inserts that require extensive machining before hardening. - **Aerospace Forgings**: Rough-machined structural components that will be aged after final machining. - **Defense Components**: Missile casings and firearm receivers machined to near-final dimensions. - **Prototype Development**: Allows easy modification and testing before commitment to final aging. - **Welded Fabrications**: Complex assemblies welded in soft condition, then aged as complete unit. - **Research & Development**: Material testing and process development in intermediate state. --- ## Processing Considerations 1. **Storage**: Annealed material should be protected from corrosion; slight surface oxidation acceptable. 2. **Machining**: Use positive rake tools, moderate speeds/feeds; produces continuous chips. 3. **Stress Relief**: Not required after machining; aging treatment will relieve machining stresses. 4. **Intermediate Aging**: Partial aging (e.g., 480°C for 1 hour) sometimes used for stability during complex machining. 5. **Surface Protection**: Annealed surface may be treated with temporary protectants during storage/machining. --- ## Transformation to Aged Condition - **Aging Process**: Heat to 480°C (900°F) for 3 hours, air cool. - **Property Change**: Hardness increases from ~30 HRC to 50–54 HRC; strength doubles. - **Dimensional Change**: Uniform growth of approximately 0.04–0.06% linearly. - **Microstructural Change**: Intermetallic precipitates (Ni₃Mo, Ni₃Ti) form in martensitic matrix. --- ## Quality Assurance - **Certification**: Mill certificates confirming chemical composition and annealing parameters. - **Hardness Testing**: 100% lot testing to ensure proper annealed condition. - **Ultrasonic Inspection**: Detect internal discontinuities in soft condition where sensitivity is higher. - **Microcleanliness**: ASTM E45 inclusion ratings typically specified. --- ## Remarks AISI Grade 18Ni (300) Maraging Steel in the nominal annealed condition represents the optimal state for fabrication of complex, high-precision components. Its combination of moderate strength, excellent machinability, and predictable transformation during subsequent aging makes it indispensable for manufacturing ultra-high-strength components with tight tolerances. Proper handling and processing in the annealed condition are critical to achieving the full performance potential after age hardening. -:- For detailed product information, please contact sales. -: AISI Grade 18Ni (300) Maraging Steel nominal annealed properties Specification Dimensions Size： Diameter 20-1000 mm Length <7333 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 (300) Maraging Steel nominal annealed properties Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Grade 18Ni (300) Maraging Steel nominal annealed properties -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Grade 18Ni (300) Maraging Steel nominal annealed properties -:- For detailed product information, please contact sales. -:

Packing of AISI Grade 18Ni (300) Maraging Steel nominal annealed properties -:- 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 3804 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