AMS 5878
AMS 5878 is the SAE Aerospace Material Specification for Haynes Alloy 230 (UNS N06230) nickel-chromium-tungsten-molybdenum alloy in bar, forging, and ring product forms. Alloy 230 (57% Ni, 22% Cr, 14% W, 2% Mo, 0.3% Al, La) is one of the highest-performing commercially available solid-solution-strengthened nickel alloys for continuous high-temperature service, maintaining useful strength to 2100°F (1150°C) with outstanding oxidation resistance and long-term microstructural stability. AMS 5878 bar and forgings are used for precision machined combustion zone components, transition duct fittings, and structural brackets in both aerospace and industrial gas turbines operating at the highest temperature levels.
The tungsten addition in Alloy 230 provides solid-solution strengthening that is uniquely stable at very high temperatures, where the strengthening contributions from other elements (Cr, Mo, Al) diminish. This makes Alloy 230 superior to many other nickel alloys for sustained load-bearing at 1800–2100°F service temperatures. AMS 5878 sets aerospace-quality requirements for composition, cleanliness, and mechanical properties in bar and forging forms.
AMS 5878 Alloy 230 bar in the solution annealed condition develops minimum 115,000 psi UTS with minimum 40% elongation at room temperature. At 1800°F (982°C), the alloy retains approximately 18,000 psi UTS — providing meaningful load-carrying capacity in gas turbine combustion zone structures that would have collapsed in conventional austenitic stainless steels. The stable M₆C carbide dispersion that forms on aging at service temperatures contributes to stress rupture life, enabling design for extended service intervals in gas turbine hot section components.
- Gas turbine combustion liner structural members and end caps
- Combustor transition duct machined fittings
- Flame holder structural components and anchor brackets
- Industrial gas turbine ring segments and seal supports
- Aerospace afterburner structural support rings and brackets
AMS 5786 — Hastelloy N Bar
Ni-Mo alloy with exceptional resistance to molten fluoride salts — the unique specification material for advanced molten salt reactor systems.
AMS 5838 — Hastelloy S Sheet
Ni-Cr-Mo alloy with low thermal expansion for gas turbine combustion zone hardware subject to severe thermal cycling.
Certified Material for Critical Service
AMS 5878 certifications include chemical composition per heat (with tungsten and lanthanum content documented), mechanical properties at room and elevated temperatures where specified, grain size, solution anneal condition, and inclusion rating per AMS 2301. For gas turbine engine applications, additional requirements may include stress rupture life testing, elevated-temperature tensile testing at 1600–2000°F, and oxidation test exposure per the applicable engine manufacturer qualification specification. Full heat-lot traceability is maintained per AS9100.