Maraging 350 is a high-strength nickel-cobalt maraging steel designed for applications requiring ultra-high strength combined with good fracture toughness. Unlike conventional hardened steels, it achieves its mechanical properties through a metallurgical reaction that does not rely on carbon. The alloy is strengthened by intermetallic compounds precipitated during aging heat treatment.

1. Operating Limits & Selection Criteria

This grade represents the upper tier of the maraging steel family. Selection is driven by strength requirements rather than corrosion or temperature resistance.

• Strength Level: Capable of achieving tensile strengths up to approximately 2400 MPa (350 ksi) after full aging treatment. The"350"designation refers to this nominal tensile strength in ksi.

• Service Temperature Range: Optimal for ambient and moderately elevated temperatures. Not intended for high-temperature creep service or cryogenic applications without specific evaluation.

• Toughness vs. Strength Trade-off: Provides higher strength than Maraging 300 but with slightly reduced fracture toughness. Select based on whether maximum strength or damage tolerance is the primary design driver.

• Corrosion Resistance: Limited. Not a stainless steel. Requires protective coating or plating for corrosive environments.

2. Manufacturing Data & Specifications

• Chemical Composition (Typical)

  Element	Content (%)
  Iron (Fe)	63 (Balance)
  Nickel (Ni)	17-19
  Cobalt (Co)	11-13
  Molybdenum (Mo)	4.6-5.2
  Titanium (Ti)	1.2-1.6
  Aluminum (Al)	0.05-0.15
  Carbon (C)	0.030 max
  Manganese (Mn)	0.10 max
  Silicon (Si)	0.10 max
  Sulfur (S)	0.010 max
  Phosphorus (P)	0.010 max
  Zirconium (Zr)	0.01
  Boron (B)	0.003

• Physical Properties

  Property	Metric	Imperial
  Density	8.08 g/cm³	0.292 lb/in³
  Elastic Modulus	200 GPa	29,000 ksi

• Mechanical Properties (Aged Condition)

  Property	Metric	Imperial
  Tensile Strength	Min. 2400 MPa	Min. 350 ksi
  Yield Strength (0.2% offset)	Min. 2340 MPa	Min. 340 ksi
  Elongation at Break	6-10%	6-10%
  Reduction of Area	35-50%	35-50%
  Fracture Toughness (KIC)	35-50 MPa√m	32-45 ksi√in

• Fabrication & Heat Treatment

  • Solution Annealed Condition: Supplied in the soft condition (approximately 30-35 HRC) for machining. All conventional machining operations can be performed prior to final hardening.

  • Aging Heat Treatment: Performed at 480-500°C (900-930°F) for 3-6 hours, followed by air cooling. This precipitation hardens the alloy to full strength with minimal dimensional change (0.05-0.10% shrinkage).

  • Welding: Can be welded in the annealed condition using matching filler metal. Post-weld aging restores properties to the weld and heat-affected zone.

3. Applications

Maraging 350 is specified where weight reduction and maximum strength are required in highly stressed components:

• Aerospace: Missile and rocket motor cases, landing gear components, ejection seats

• Defense: Armor, ordnance components

• Power Transmission: High-performance shafts, gears, couplings for helicopters and jet engines

• Motorsports: Drivetrain components, suspension parts, racing fasteners

• Tooling: Die casting pins, cores, and high-pressure molds

4. Available Product Forms & Supply

For engineers and procurement specialists requiring ultra-high-strength steel for mission-critical applications, ZYTC Alloy stocks certified Maraging 350 (UNS S35000) in multiple forms:

• Bar, Rod, Billet (up to 18"diameter)

• Plate and Sheet

• Seamless and Welded Pipe & Tube

• Custom Forgings

All material is supplied with full traceability and certification, suitable for aerospace, defense, and high-performance industrial applications. Contact ZYTC Alloy for stock availability and pricing.

Email: daisy@zytcsteel.com

WhatsApp/WeChat: +86 17335753350