GH738 Nickel base superalloyGH738 corresponding grades: GH4738, NC20K14, 2.4654, UNS N07001, WaspaloyOverview of GH738: GH738 is a nickel-based superalloy with γ' phase precipitation hardening, which has good gas corrosion resistance, high yield strength and fatigue performance, good process plasticity and stable structure. ***Used for rotating parts of aero-engine, the operating temperature is not higher than 815ºC. GH738 can produce cold-rolled and hot-rolled sheet, pipe, strip, wire and forgings, castings, fasteners.2. Performance
GH4738 alloy has good oxidation resistance and corrosion resistance in various atmospheres encountered in jet engines or similar I working conditions. The oxidation resistance temperature of continuous operation can reach 1040 ° C, and the intermittent operation can be Up to 870°C, the alloy has good resistance to salt spray corrosion, especially the solution treated state is the best. After the bar was treated at 1080°Cx4h/AC+stabilization+aging, the notch persistence experiments at 650°C, 750°C and 815°C showed that the gold had no defect sensitivity. After long-term aging at 650°C and 730°C for 3000h, the alloy has no new phase precipitation, and the structure is stable.
3. Use
GH4738 alloy has been used to make turbine disks, blades and sealing rings of aero-engines, as well as flue gas turbine blades, turbine disks and large bolts. The alloy is widely used abroad in the fields of rotating parts of aviation, aerospace, petroleum, chemical and power generation equipment, such as compressor blades, turbine disks, valve bodies, annular parts and shafts and other rotating parts.
Note: Trace impurities are ω(Pb)≤0.001%, ω(As)≤0.0025%, ω(Sn)≤0.0012%, ω(Sb)≤0.0025%, ω(Bi)≤0.0001%.
GH738 heat treatment system: 1080ºC±10ºC, 4h, air cooling +840ºC, 24h, air cooling +760ºC, 16h, air cooling.
GH738 varieties, specifications and supply status: can produce bars, profiles, forging billets, rings, thick plates, thin plates, strips, pipes, wires, sand castings, stainless steel castings and fasteners, etc., usually without heat treatment Delivery, the plate is delivered after solution treatment.
GH738 melting and casting process: vacuum induction melting and vacuum arc remelting process are adopted.
Application overview and special requirements of GH738: This alloy is widely used in aero-engines and gas turbines abroad, mainly used for rotating parts such as turbine blades and turbine pans, and has mature experience in use. Due to the high cobalt content of this alloy, the cost is high, and it is rarely used in China.
Chemical composition
Carbon C: (0.03~0.10)
Silicon Si: (0.15)
Manganese Mn: (0.10)
Chromium Cr: (18.0~21.0)
Nickel Ni: (Balance)
Aluminum Al (1.20~1.60)
Molybdenum Mo: (3.50~5.00)
Iron Fe (2.0)
Sulfur s (0.015)
Phosphorus p (0.015)
Titanium Ti (2.75~3.25)
Copper Cu: (0.10)
Zirconium zr (0.02~0.08)
Boron B (0.003~0.010)
Melting temperature range of GH738: 1330~1360ºC.
GH738 density: ρ=8.22g/cm3.
GH738 Magnetic properties: The alloy is non-magnetic.