GH4145 Material introduction
GH4145 It is a Ni Cr based precipitation hardening deformed superalloy, mainly composed of γ＇ The phase is aging precipitation strengthening phase, and the service temperature is below 800 ℃. The alloy has good corrosion resistance and oxidation resistance below 980 ℃, high strength below 800 ℃, good creep resistance below 700 ℃, and good relaxation resistance below 540 ℃. The alloy also has good formability and weldability. The main products are plates, strips, bars, profiles, forgings, rings, wires and pipes.
The alloy has been used to manufacture annular parts, structural parts, bolts and other parts with high strength and corrosion resistance for aeroengines operating below 800 ℃, plane wave springs, circumferential spiral springs, spiral compression springs, spring clips and seals with medium or low stress and anti relaxation for engines operating below 540 ℃, and gas turbine blades and other parts.
The alloy can be welded after annealing or solution treatment. Heat treatment of parts shall be carried out in sulfur free neutral or reducing atmosphere to avoid vulcanization. Parts shall not be heated between 870 ℃ and 650 ℃ ↔ Cold "treatment: for parts with large section, in order to prevent cracks, they should be cooled in air after solution treatment.
GH4145 chemical composition
element | C | Cr | Ni | Co | Al | Ti | Fe |
mass fraction／% | ≤0.08 | 14.0-17.0 | ≥70.0 | ≤1.0 | 0.4-1.0 | 2.25-2.75 | 5.0-9.0 |
element | Nb | Mn | Si | S | P | Cu |
|
mass fraction／% | 0.7-1.2 | ≤1.0 | ≤0.5 | ≤0.01 | ≤0.015 | ≤0.50 |
|
GH4145 Physical and mechanical properties
density | melting point |
8.25g/cm³ | 1395～1425℃ |
varieties | Heat treatment method | σb/MPa | σp0.2/MPa | δ5/% | Ψ/%
| HBS
|
Strip | Solution+aging | ≥1105 | --- | --- | --- | ≥30 |
board | Solution+aging | ≥1170 | ≥795 | --- | --- | ≥32 |
GH4145 Heat treatment system
Cold rolled sheet, cold rolled strip, capillary
A)Supply status：980℃±10℃/AC Or quick cooling；
B)Aging treatment：730℃±10℃×8h/FC(55℃/h) →620℃±10℃×8h/AC，Or the FC rate is not limited, but the total holding time shall not be less than 18h。
Cold drawn wire
systemⅠ：650℃±10℃×4h/AC；
systemII：1150℃±10℃×2h/AC+840℃±10℃×24h/AC+705℃±10℃×20h/AC;
systemⅢ：730℃±10℃×16 h/AC。
Standard Heat Treatment for Bars and Forgings
885℃±14℃×24h±0.5h/AC+705℃±10℃×20h±l h/AC。
Special heat treatment of bars and forgings
A) Use below 595 ℃：(870~900)℃×24h/AC+(690~720)℃×30h/AC；
B)（970~995）℃×l h/AC+(725~740)℃×8h/FC(550℃/h)→(615~630)℃/AC，Total heat preservation time 18h。
