Discover the latest trends and innovations in the nickel alloy industry. We provide expert insights and in-depth analysis on the newest developments in nickel alloys.
GH1131, old drawing name GH131, is a Fe-Ni-Cr base, solid-solution strengthened wrought superalloy under GB/T 14992-2005 (ISC H11310). It is not nickel-base, it has no γ′ phase, and it is not age-hardenable. What it does is hold 700–750℃ under low-to-medium stress for long stretches, take 900℃ continuously, survive 1000℃ for short excursions, and still weld and deep-draw like a sheet alloy should. In Chinese engine shops it is the default iron-base choice for afterburner cans, combustion chamber skins, rocket thrust-chamber jackets, and flame-holder brackets—places where a nickel-base like GH3044 would work but cost too much, and a plain 310S stainless would oxidize and sag.
Russian cross-equivalent is Х21Н28В5М3БАР / ЭЛ126; there is no direct AMS number because it is not a Western development. People sometimes try to map it to Haynes 556 or 230—wrong family. Haynes 556 is Fe-Ni-Cr with Nb+N, but Cr/Ni/W/Mo levels and the N 0.15–0.30% trick are not the same; GH1131 stands on its own.
1. Chemistry: why W hits 6% and N hits 0.3%
Typical GB/T 14992 envelope (wt%):
Fe: balance (~48–53)
Ni: 25.0–30.0 (stabilizes austenite, keeps it nonmagnetic, buys ductility)
Cr: 19.0–22.0 (Cr₂O₃ scale, oxidation to ~1000℃)
W: 4.80–6.00 (main solid-solution hardener, atomic-size strain)
Mo: 2.80–3.50 (W partner, drags dislocation climb)
Nb: 0.70–1.30 (Z-phase (W,Nb)CrN + NbC, pins boundaries)
N: 0.15–0.30 (interstitial, refines grains, supplements Z-phase)
C: ≤0.10 (kept low, no heavy carbide network)
B: ≤0.005; Mn ≤1.20; Si ≤0.80; P ≤0.020; S ≤0.020; Cu ≤0.50
Al/Ti: only trace (≤0.5 each), not enough for γ′—this is the line that separates GH1131 from precipitation alloys like GH4169 or GH4738
The design logic is crude but effective: push Ni to ~28% so the matrix stays FCC and tough, dump W+Mo to ~9% total so the lattice is stiff at 750℃, add N+Nb so the grain boundaries do not slide, and keep Cr at 20% so the skin does not burn. No aging, no γ′ solvus to track—just one solid-solution anneal and go.
2. What "solid-solution strengthened" means here mechanically
Room temperature (solution-treated sheet/bar, typical mill floor values):
Rm ≥735 MPa (many mills ship 800–950 MPa depending on thickness and slight cold correction)
Rp0.2 ≥343 MPa
A₅ ≥32% (thin sheet often 35–45%)
Impact and bend behave like an austenitic stainless with extra drag
Elevated temperature:
750℃: Rm in the 550 MPa class, usable for liner supports and low-stress structure
900℃: Rm 175–190 MPa, A still 35%+ — this is where it earns its keep as a formable hot sheet
1000℃: Rm ≥108 MPa, A ~40–50%; not a load-bearing number, just confirms it will not shatter during a transient
Creep wise: 850℃/100 MPa class gives hundreds of hours, not the 10⁴ h you get from Waspaloy. That is fine—GH1131 is not a disk alloy. It is a 700–750℃ long-term, 900℃ continuous, 1000℃ short-time sheet/structure alloy.
3. Oxidation numbers people actually use
Air, 100 h test, mass gain rate:
900℃: 0.131 g/(m²·h)
950℃: 0.156
1000℃: 0.186
1010℃: 0.447 (scale starts breaking down, not a service point)
So the honest oxidation ceiling is ~1000℃ for static exposure; 900℃ is the comfortable liner temperature, 1000℃ is for a few hundred hours max. Past 1010℃ the rate jumps and you are into nickel-base or coated territory.
4. Microstructure and long-term stability
Solution-treated condition:
Fully recrystallized austenite (sheet ASTM 4–6, thin sheet 5–7)
Scattered primary Z-phase (W,Nb)CrN and trace NbC, total ~1.0–1.5% by volume, no continuous grain-boundary film
No γ′, no primary σ
Aging exposure 700–950℃ for thousands of hours throws out a little L-phase (Fe-Mo-W TCP) and some M₆C, but the amount saturates—does not run away like σ in some Fe-Ni-Cr grades. Trade-off: after 5000–10000 h the room-temperature elongation can drift from ~32% down to ~20–25%. It does not crack by itself; it just means you do not re-qualify a 10-year-old liner with fresh-sheet ductility values.
5. Heat treatment (only one real step)
No aging. The whole book is solid solution:
Sheet (≤3 mm): 1130–1170℃ × 8–12 min, air cool
Sheet (3–5 mm): 1130–1170℃ × 12–16 min, AC
Plate/bar: 1160℃±10℃ × per diameter, air cool
Part final anneal: 1150℃±10℃ or 1080–1120℃ AC; intermediate stress relief 1000℃±10℃ AC
Forging: start >980℃, finish ≥900℃
If a supplier quotes "GH1131 peak aged" or "GH131 precipitation hardened", they mixed it with GH4169. Send it back.
6. Standards chain (mother grade + product spec)
Mother grade: GB/T 14992-2005, H11310, class "1" iron-base solid-solution wrought
Cold-rolled sheet/strip: GB/T 14996, GJB 1952A (aviation), GJB 1954 (space)
Hot-rolled plate: GB/T 14995, GJB 3317
Bar/forging: YB/T 5245 (general load), GJB 3165 (aviation load), GJB 2611 (cold-drawn), GJB 3020 / GJB 3782 (ring/disk blank)
Wire/filler: GJB 2612, GJB 3167
Heat treat practice ref: HB/Z 140
Melting: non-VIM induction + ESR, or arc furnace + ESR; single arc furnace without ESR is not accepted for aviation-grade plate
