Nickel Alloy N08221-ANN (Annealed)
Heat-treated state · default condition
UNS N08221
Standard stocked condition for plate, sheet, bar, pipe and fittings — maximum corrosion resistance and ductility.
Values for the ANN condition
Other N08221 tempers and conditions
N08221 is listed in 5 conditions; see the grade overview at N08221.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Finished, Annealed | Heavy plate, forged bar and seamless pipe route; same metallurgy as annealed but coarser grain and scaled/pickled surface. | 285 | 630 | 45 | 165 HB | 1.5 % IACS |
ANNDefaultThis page Annealed | Standard stocked condition for plate, sheet, bar, pipe and fittings — maximum corrosion resistance and ductility. | 300 | 650 | 48 | 170 HB | — |
Cold Drawn, Annealed | Choose for close-tolerance bar and instrument tubing where full corrosion resistance is still required. | 310 | 660 | 45 | 175 HB | 1.5 % IACS |
As-welded deposit | Condition of fabricated vessels and piping when solution annealing after welding is impractical; expect dendritic segregation and slightly lower pitting resistance in the fusion zone. | 340 | 640 | 35 | 190 HB | 1.5 % IACS |
Cold worked | Use when higher strength or hardness is needed for fasteners, shafting and springs; corrosion resistance and ductility are somewhat reduced. | 650 | 860 | 22 | 24 HRC | — |
What is N08221-ANN?
N08221-ANN is N08221 heat treated to ANN — standard stocked condition for plate, sheet, bar, pipe and fittings — maximum corrosion resistance and ductility. N08221-ANN has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 78% of nickel alloy grades. Elongation at break is 48% and the elastic modulus is 200 GPa (29 Msi). N08221-ANN has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 80% of nickel alloy grades. It melts at 1,330°C (2,426 °F).
Advantages
- Polishes to a fine finish — 80/100, better than 97% of nickel alloy grades
- Ductile — tolerates forming and impact — 48%, better than 83% of nickel alloy grades
Limitations
- Low strength — 300 MPa (43.5 ksi), worse than 78% of nickel alloy grades
- Limited service temperature — 500°C (932 °F), worse than 78% of nickel alloy grades
N08221-ANN properties
Typical room-temperature values for N08221-ANN; 13 are specific to this condition. Other listed values are N08221 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
N08221-ANN has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 80% of nickel alloy grades. It melts at 1,330°C (2,426 °F).
Mechanical13
N08221-ANN has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 78% of nickel alloy grades. Elongation at break is 48% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
N08221-ANN is rated for continuous service to 500°C (932 °F). It conducts heat at 11 W/m·K (6.36 BTU/hr·ft·°F), worse than 60% of nickel alloy grades. Thermal expansion is 13.6 µm/m·K (7.56 µin/in·°F).
Electrical3
N08221-ANN conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (84/100), better than 70% of nickel alloy grades.
Sustainability4
Producing a kilogram of N08221-ANN takes about 155 MJ of energy and emits 13 kg of CO₂ — less than 58% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability8
N08221-ANN's machinability is poor (24/100, better than 71% of nickel alloy grades); weldability very good (78/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with N08221-ANN
Is N08221 easy to machine?
Treat as a gummy, work-hardening nickel alloy: rigid setup, positive-rake sharp carbide, 15–30 m/min turning, heavy positive feed to stay under the hardened skin, and flood high-pressure coolant.
Can N08221 be welded?
GTAW/GMAW/SMAW with matching or slightly over-alloyed Ni-Cr-Mo filler, low heat input, stringer beads, interpass below ~150 °C; back-purge with argon and pickle/passivate afterwards.
Can N08221 be formed, bent or molded?
Cold forms well from the annealed condition but work-hardens fast — allow 30–50 % more press force than 304 and interstage anneal at ~1120–1180 °C with rapid quench; hot work roughly 1150–1200 °C down to 950 °C.
What surface finishes work on N08221?
No anodizing; finish by pickling in HNO3-HF, mechanical polishing or electropolishing, and always remove weld heat tint to restore full pitting resistance.
N08221 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 |
|---|---|---|
| Niindicative class value for the Ni-Fe-Cr-Mo UNS N082xx family — confirm against the governing UNS/ASTM registration for N08221 | 30 – 45 | 37 |
| Crindicative class value — verify against governing specification | 19 – 24 | 21.5 |
| Moindicative class value — verify against governing specification | 4 – 7 | 5.5 |
| Cutypical for acid-service Fe-Ni-Cr-Mo grades; verify | 0 – 2 | 1 |
| Mnindicative | 0 – 2 | 0.8 |
| Siindicative | 0 – 0.8 | 0.3 |
| Clow-carbon corrosion grade, indicative | 0 – 0.03 | 0.02 |
| Nnitrogen-alloyed for pitting resistance, indicative | 0 – 0.25 | 0.15 |
| Presidual limit, indicative | ≤ 0.03 | — |
| Sresidual limit, indicative | ≤ 0.01 | — |
| Fe | balance | — |
N08221-ANN — frequently asked
What is N08221-ANN used for?
N08221-ANN is typically used for chemical processing equipment, acid handling components and process piping. In short: superaustenitic acid-service alloy; welds without post-weld anneal; limited stock availability.
What is the yield strength of N08221-ANN?
N08221-ANN has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 78% of nickel alloy grades. Strength varies by condition: see the 5 listed tempers.
Is N08221-ANN easy to machine?
Not especially — machinability is rated poor (24/100, better than 71% of nickel alloy grades). Treat as a gummy, work-hardening nickel alloy: rigid setup, positive-rake sharp carbide, 15–30 m/min turning, heavy positive feed to stay under the hardened skin, and flood high-pressure coolant.
Can N08221-ANN be welded?
Yes — weldability is rated very good (78/100). GTAW/GMAW/SMAW with matching or slightly over-alloyed Ni-Cr-Mo filler, low heat input, stringer beads, interpass below ~150 °C; back-purge with argon and pickle/passivate afterwards.
What surface finishes work on N08221-ANN?
No anodizing; finish by pickling in HNO3-HF, mechanical polishing or electropolishing, and always remove weld heat tint to restore full pitting resistance.
Can N08221-ANN be formed, bent or molded?
Cold forms well from the annealed condition but work-hardens fast — allow 30–50 % more press force than 304 and interstage anneal at ~1120–1180 °C with rapid quench; hot work roughly 1150–1200 °C down to 950 °C.
What is the maximum service temperature of N08221-ANN?
N08221-ANN is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between N08221-ANN and N08221-CW?
ANN is the default condition — standard stocked condition for plate, sheet, bar, pipe and fittings — maximum corrosion resistance and ductility. CW: use when higher strength or hardness is needed for fasteners, shafting and springs; corrosion resistance and ductility are somewhat reduced. Yield strength is 300 MPa in ANN versus 650 MPa in CW.
Sources
- Metals & Alloys in the Unified Numbering System (UNS) — SAE International / ASTM (2021)
- ASTM B575 / B424 / B564 — Ni-Cr-Mo and Ni-Fe-Cr-Mo plate, sheet, strip, bar and forgings — ASTM (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys — ASM International (2000)
- Nickel Institute technical series — corrosion-resistant Ni-Fe-Cr-Mo alloys — Nickel Institute (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.