GH2901 high temperature alloy steel composition, standards, performance introduction
Product name: precipitation hardening deformation high temperature alloy
Product brand: GH2901
Corresponding brands: China ((GH761,761)), Incoloy901 (US), Nimonic901 (UK), 2·4662 (Germany)
Product form: bars, pipes, plates, rings, forgings
Delivery status: hot rolling, cold rolling, solution, aging
GH2901 chemical composition:
C: 0.02-0. 06
Cr: 11.0-14.0
Ni: 40.0-45.0
Mo: 5.0-6.50
Al: 0.30
Ti: 2.80-3.10
Fe: balance
B: 0.010-0.020
Mn: 0.50
Si: 0.40
P: 0.020
S: 0.008
Cu: 0.20
GH2901 implementation standard:
GB/T 14992 Classification and grades of high-temperature alloys and intermetallic compound high-temperature materials
GJB 5280 Specification for high-temperature alloy disc forgings for aircraft engines
GJB 5301 Specification for high-temperature alloy rings for aircraft use
HB/Z 140 Heat treatment process for high-temperature alloys for aircraft use
WS9-7029 billet GH901 alloy bar for shafts
WS9-7029 bar GH901 alloy bar for rotating parts
WS9-7031 GH901 alloy hot-rolled and forged bar
QJ/DT 0160013 Technical conditions of GH901 bars for gas turbines
GH2901 mechanical properties:
Temperature/°C: 20-575
Tensile strength b\MPa: ≥1130-960
Elongation A/%: ≥9-8
Shrinkage Z/%: ≥12
Density g/cm³: 8.21
Melting temperature: 1360°C
Brinell hardness HBS: ≥341
GH2901 melting process:
Non-vacuum induction furnace + vacuum arc remelting + vacuum arc remelting, or vacuum induction furnace + electroslag remelting, or vacuum induction furnace + vacuum arc remelting melting process.
Heat treatment system:
1090℃±10℃, 2~3h, water cooling or oil cooling +775℃±5℃, 4h, air cooling +700~720℃, 24h, air cooling.
Solution treatment at 11090℃ for 180 minutes, water cooling or air cooling, aging treatment at 775℃ for 4 hours, air cooling + 705-725℃ for 24 hours, air cooling.
Main characteristics of GH2901:
GH2901 is a Fe-Ni-Cr based precipitation hardening deformation high temperature alloy. The alloy is aged and strengthened with the metastable γ[Nij(Ti,A1)] phase, and a trace amount of aluminum inhibits the transformation of γ to ヶNiTi phase. The alloy has high yield strength and endurance strength below 650℃, good oxidation resistance below 760℃, and stable organization for long-term use.
GH2901 alloy has no notch sensitivity after standard heat treatment and long-term aging at different times in the range of 550℃~750℃. However, when forging, if the process parameters are not selected or operated properly, long strips or flakes of harmful phases TizSC and large granular boride and Ti(CN) phases may precipitate at the grain boundaries after standard heat treatment, resulting in notch sensitivity during endurance testing. At this time, it is impossible to eliminate notch sensitivity through heat treatment, and only re-heat processing and deformation can obtain a suitable structure. The expansion coefficient of the alloy is close to that of ferrite heat-resistant alloy steel, so that the two materials can be connected without special regulations on thermal expansion.
GH2901 application areas:
GH2901 alloy has been used to make rotating parts and fasteners for aircraft engines and ground gas turbines, and the alloy parts have a long service life.
(Supplement) Numerical values of creep and fatigue of GH2901 nickel-based alloy:
GH2901 alloy is a Fe-Ni alloy with high Ni content, with face-centered cubic γ′[Ni_3(Al,Ti)] as strengthening phase, and a certain amount of Mo is added for solid solution strengthening. In order to improve the grain boundary strength of the alloy at high temperature, a trace amount of B is added to strengthen the grain boundary. Due to the sensitivity of the alloy structure and performance to hot working parameters, as well as the special requirements of special forgings for metal streamlines, improper selection of forging, heat treatment process methods and parameters can easily cause surface cracks on forgings. This paper summarizes a more reasonable production process through crack cause analysis and process comparison tests.
Taking GH2901 high temperature alloy as the research object, the relationship curve between creep strain and time under constant uniaxial tensile force of 730 MPa and 850 MPa at 500℃ was experimentally determined. Then, based on the curve, the combined time-enhanced creep constitutive equation was used to fit the function and the corresponding creep constitutive equation was obtained. Through the equation, the strain law and service life of the alloy were obtained by creep finite element calculation and fatigue life calculation. The analysis results show that when the alloy is subjected to constant stress of 730 MPa at 500℃ for 10h, the creep strain value is 0.002553~0.010767, and the total strain value is 0.0027544~0.012411. The data show that the rate-independent strain value (elastic strain plus rate-independent plastic strain) is very small compared to the creep strain value (rate-dependent plastic strain), which is about 1/10 of it.
