Nickel Alloy Waspaloy · heat-treated state
Nickel Alloy Waspaloy-STA
Properties of the STA condition, compared with the other Waspaloy tempers.
Standard high-strength fully heat-treated condition for discs, shafts and fasteners used up to ~700 °C.
What is Waspaloy-STA?
Waspaloy-STA is Waspaloy heat treated to STA — standard high-strength fully heat-treated condition for discs, shafts and fasteners used up to ~700 °C. Waspaloy-STA has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,350 MPa (196 ksi) — stronger than 94% of nickel alloy grades. Elongation at break is 24% and the elastic modulus is 211 GPa (30.6 Msi). Waspaloy-STA has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 67% of nickel alloy grades. It melts at 1,330°C (2,426 °F). Solution Annealed is the default condition FabDigit quotes; STA is available on request or by drawing note.
Advantages
- High strength — 900 MPa (131 ksi), better than 94% of nickel alloy grades
Limitations
- High embodied carbon — 15.5 kg CO₂/kg, worse than 90% of nickel alloy grades
- Difficult to weld — 20/100, worse than 85% of nickel alloy grades
- Limited formability — 12/100, worse than 85% of nickel alloy grades
Waspaloy-STA properties
Typical room-temperature values for Waspaloy-STA — 16 properties are specific to this condition; the rest are grade-level values shared by every Waspaloy temper. Each bar shows where the value sits among the nickel alloy grades in FabDigit's library — further right is higher.
Physical3
Waspaloy-STA has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 67% of nickel alloy grades. It melts at 1,330°C (2,426 °F).
Mechanical15
Waspaloy-STA has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,350 MPa (196 ksi) — stronger than 94% of nickel alloy grades. Elongation at break is 24% and the elastic modulus is 211 GPa (30.6 Msi).
Thermal6
Waspaloy-STA is rated for continuous service to 705°C (1,301 °F). It conducts heat at 10.7 W/m·K (6.18 BTU/hr·ft·°F), worse than 68% of nickel alloy grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
Waspaloy-STA conducts electricity at 1.4 % IACS, worse than 66% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (74/100), worse than 66% of nickel alloy grades.
Sustainability4
Producing a kilogram of Waspaloy-STA takes about 235 MJ of energy and emits 15.5 kg of CO₂ — more than 94% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability8
Waspaloy-STA's machinability is not recommended (12/100, worse than 87% of nickel alloy grades); weldability poor (20/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Waspaloy tempers and conditions
Waspaloy is also supplied in 4 other conditions. The full side-by-side table is on the Waspaloy overview.
- Solution AnnealedDefaultMill-supplied soft condition for machining, forming and welding before final age hardening.520 MPa yield · 24 HRC
- CD+ACold-drawn small-diameter bar and wire aged for bolts and studs where extra strength and straightness are needed.1,000 MPa yield · 40 HRC
- STAStandard high-strength fully heat-treated condition for discs, shafts and fasteners used up to ~700 °C.900 MPa yield · 36 HRC
- STA-HSCoarser-grain high-solution treatment: slightly lower RT strength but best creep-rupture life above 730 °C.830 MPa yield · 34 HRC
Working with Waspaloy-STA
Is Waspaloy easy to machine?
Machine in the solution-annealed state where possible; rigid setups, positive-rake carbide or ceramic/whisker tools, low surface speed with heavy flood coolant, constant feed to avoid work-hardened glaze and notching.
Can Waspaloy be welded?
GTAW/EB/laser welding with matching Waspaloy or Alloy 625/263 filler on solution-annealed material only; age after welding and control restraint to avoid strain-age (post-weld heat treat) cracking.
Can Waspaloy be formed, bent or molded?
Hot work 1050–1150 °C with tight temperature control and rapid cooling; cold forming of annealed sheet needs high loads and frequent intermediate solution anneals.
What surface finishes work on Waspaloy?
No anodizing; typical finishing is grinding/lapping, shot peening for fatigue life, pickling or vacuum cleaning, and optional aluminide/thermal-barrier coatings for hot-section parts.
Waspaloy chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cr | 18 – 21 | 19.5 |
| Co | 12 – 15 | 13.5 |
| Mo | 3.5 – 5 | 4.3 |
| Ti | 2.75 – 3.25 | 3 |
| Al | 1.2 – 1.6 | 1.4 |
| Fe | ≤ 2 | 0.7 |
| C | 0.02 – 0.1 | 0.05 |
| Zr | 0.02 – 0.08 | 0.05 |
| B | 0 – 0.01 | 0.01 |
| Mn | ≤ 0.1 | 0.03 |
| Si | ≤ 0.15 | 0.05 |
| Cu | ≤ 0.1 | 0.02 |
| P | ≤ 0.02 | — |
| S | ≤ 0.02 | — |
| Nibalance, typically ~57–58 % | balance | — |
Waspaloy-STA — frequently asked
What is Waspaloy-STA used for?
Waspaloy-STA is typically used for turbine disks and hubs, turbine blades and vanes, engine shafts and spacers, seal rings and labyrinth seals, high-temperature bolting and fasteners and gas turbine casings and rings. In short: disc-grade aerospace superalloy.
What is the yield strength of Waspaloy-STA?
Waspaloy-STA has a typical yield strength of 900 MPa (131 ksi) and a tensile strength of 1,350 MPa (196 ksi) — stronger than 94% of nickel alloy grades. Strength varies by condition: see the 5 listed tempers.
Is Waspaloy-STA easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 87% of nickel alloy grades). Machine in the solution-annealed state where possible; rigid setups, positive-rake carbide or ceramic/whisker tools, low surface speed with heavy flood coolant, constant feed to avoid work-hardened glaze and notching.
Can Waspaloy-STA be welded?
Not readily — weldability is rated poor (20/100). GTAW/EB/laser welding with matching Waspaloy or Alloy 625/263 filler on solution-annealed material only; age after welding and control restraint to avoid strain-age (post-weld heat treat) cracking.
What surface finishes work on Waspaloy-STA?
No anodizing; typical finishing is grinding/lapping, shot peening for fatigue life, pickling or vacuum cleaning, and optional aluminide/thermal-barrier coatings for hot-section parts.
Can Waspaloy-STA be formed, bent or molded?
Hot work 1050–1150 °C with tight temperature control and rapid cooling; cold forming of annealed sheet needs high loads and frequent intermediate solution anneals.
What is the maximum service temperature of Waspaloy-STA?
Waspaloy-STA is rated for continuous use to about 705°C (1,301 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Waspaloy Solution Annealed and Waspaloy-STA?
Solution Annealed is the default condition — mill-supplied soft condition for machining, forming and welding before final age hardening. STA: standard high-strength fully heat-treated condition for discs, shafts and fasteners used up to ~700 °C. Yield strength is 520 MPa in Solution Annealed versus 900 MPa in STA.
Can FabDigit make parts in Waspaloy-STA?
Yes — Waspaloy-STA is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- AMS 5706 / 5707 / 5708 / 5544 Waspaloy bars, forgings, rings and sheet — SAE International (2020)
- UNS N07001 designation (Metals & Alloys in the Unified Numbering System) — SAE/ASTM (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Superalloys: A Technical Guide, 2nd ed. — ASM International (2002)
- Waspaloy alloy technical data — Special Metals / Haynes / Carpenter (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.