High Temperature Tensile Strength Data of GH1131 from 700℃ to 1000℃

GH1131 (old GH131,) is a Fe-Ni-Cr base, solid-solution strengthened wrought superalloy​ per GB/T 14992-2005 (H11310). It carries Ni 25–30%, Cr 19–22%, W 4.8–6.0%, Mo 2.8–3.5%, Nb 0.7–1.3%, N 0.15–0.30%, no γ′, no aging. All tensile numbers below are for the solution-treated condition​ (sheet 1130–1170℃ AC, bar/forging 1160℃±10℃ AC). Data sources are consolidated from GB/T 14992-family mill tables, Chinese superalloy handbooks, and COCESS in-house MTR averages.

1. Room-temperature baseline (to confirm the heat is correct)

Solution-treated bar/sheet typical:

• Rm 735–882 MPa​ (many mills ship 800–945 MPa depending on section and slight cold correction)

• Rp0.2 343–380 MPa

• A₅ 32–35%​ (thin sheet 34–45%)

If a "GH1131" sample shows Rm < 700 MPa at 20℃, check the solution temperature first—not the chemistry.

2. Tensile strength 700–1000℃ (consolidated table)

Notes on scatter:

• 900℃ Rm splits by product form: handbook bar floor is ≥176–186 MPa, cold-rolled thin sheet often reports 215–235 MPa​ because of finer grain and thinner-section rapid test heating. For design, use 180 MPa​ conservative.

• 1000℃ Rm floor in GB/T 14992-family specs is ≥108 MPa; mill typical 110–137 MPa. Do not use the 137 MPa upper value for allowable stress.

• Rp0.2 above 700℃ is rarely mandated in Chinese specs; engineering practice estimates it as ~0.4–0.5 × Rm​ for this solid-solution grade, then applies a creep derate—never treat it as a precipitation-hardened alloy yield.

3. What the curve actually says

• 20→700℃: Rm retention ~67–85% of room-temp value. W+Mo+Nb+N solid-solution drag holds well; 700℃ Rm ~590 MPa is why GH1131 is booked for afterburner liners and rocket chamber jackets at 700–750℃ long-term.

• 700→800℃: Rm falls from ~590 to ~380 MPa, i.e. −35% in 100℃. This is the middle of the useful band, not a collapse yet, but 800℃ is where 100 h-class stress must be capped low (800℃/108 MPa gives 435–588 h rupture—so working stress ~80–100 MPa max).

• 800→900℃: Rm drops to ~180 MPa, another −50%. At 900℃ the alloy is a formable hot-skin material, not a loaded structure. 900℃/51 MPa rupture runs 293–300 h, which tells you sustained stress at 900℃ should sit under ~30–40 MPa.

• 900→1000℃: Rm ~110 MPa, A₅ jumps to 50–100% (specimen necks fast, no work hardening). 1000℃ is a transient number—rocket-engine few-hundred-second burns, not 10⁴ h service. Oxidation rate at 1000℃ is 0.186 g/(m²·h); at 1010℃ it jumps to a much higher rate, confirming 1000℃ is the edge.

4. Tensile vs. rupture—do not confuse them

GH1131 tensile at 800℃ Rm ~380 MPa does not​ mean 800℃/380 MPa is allowable. Rupture anchors:

• 800℃ / 108 MPa → 435–588 h

• 900℃ / 51 MPa → 293–300 h

So a rough design rule from the tensile table:

• 700℃ long-term: working stress 80–120 MPa

• 750℃ long-term: 60–100 MPa

• 900℃ continuous low-stress: 30–40 MPa

• 1000℃ short-time: <30 MPa, limited hours

Tensile Rm is the instantaneous failure load in a few minutes; GH1131 lives or dies in service by the rupture line, not by the 1000℃/110 MPa tensile figure.

5. 800℃ caution (not a data error, a microstructure fact)

Some mills report 800℃×200 h aged sheet with higher room-temperature Rm but A₅ falling to ~15%. That is not strengthening—it is incipient L-phase/Z-phase coagulation and ordering in the 700–850℃ dwell window. So even though 800℃ tensile Rm looks decent (~380 MPa), long-term dwell near 800℃ is not recommended; keep long-term metal temperature at 750℃ or below, use 800℃ only for cyclic/short exposure, and 900℃ for continuous low-stress skin.

6. One-line summary for designers

GH1131 solution-treated:

• 700℃ Rm ~590 MPa​ (long-term stressed zone)

• 800℃ Rm ~380 MPa​ (mid-life hot zone, avoid long dwell)

• 900℃ Rm ~180 MPa​ (continuous oxidation/low-stress liner zone)

• 1000℃ Rm ~110 MPa​ (short-time transient only)

It is an iron-base economizer with ~28% Ni: strong at 700℃, acceptable at 800℃, survivable at 900℃, nominal at 1000℃—and the tensile curve above is only valid if the sheet or bar has seen a real 1130–1170℃ (or 1160℃) solution anneal, not a soft anneal.