Stainless Steel N08320 Annealed
Temper · default condition
UNS N08320
Standard supply condition for plate, sheet, bar and tube in corrosive chemical process service; maximum corrosion resistance and ductility.
Values for the Annealed condition
Other N08320 tempers and conditions
N08320 is listed in 4 conditions; see the grade overview at N08320.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Finished + Annealed | Choose for heavy sections, forgings and thick plate where hot working precedes the anneal; properties essentially the same as annealed with slightly lower strength in very heavy sections. | 255 | 565 | 45 | 150 HB | 1.7 % IACS |
AnnealedDefaultThis page solution annealed ~1010–1120 °C, rapid quench | Standard supply condition for plate, sheet, bar and tube in corrosive chemical process service; maximum corrosion resistance and ductility. | 265 | 585 | 45 | 160 HB | — |
Cold drawn | Choose for fasteners, shafts and pump/valve parts needing higher strength and better dimensional tolerance than annealed bar; slightly reduced ductility and corrosion margin. | 550 | 760 | 25 | 220 HB | — |
Quarter hard | Choose for springs, diaphragms and formed strip parts where extra strength is needed and full annealed ductility is not; sensitive to stress corrosion in hot chloride service. | 620 | 860 | 18 | 25 HRC | 1.7 % IACS |
What is N08320 Annealed?
N08320 Annealed is N08320 in the Annealed temper — standard supply condition for plate, sheet, bar and tube in corrosive chemical process service; maximum corrosion resistance and ductility. N08320 Annealed has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi). N08320 Annealed has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Advantages
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
- Forms and bends easily — 72/100, better than 84% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- High embodied carbon — 6.2 kg CO₂/kg, worse than 90% of stainless steel grades
- Low strength — 265 MPa (38.4 ksi), worse than 81% of stainless steel grades
N08320 Annealed properties
Typical room-temperature values for N08320 Annealed; 15 are specific to this condition. Other listed values are N08320 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
N08320 Annealed has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical13
N08320 Annealed has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
N08320 Annealed is rated for continuous service to 500°C (932 °F). It conducts heat at 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades. Thermal expansion is 14.6 µm/m·K (8.11 µin/in·°F).
Electrical3
N08320 Annealed conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 84% of stainless steel grades.
Sustainability4
Producing a kilogram of N08320 Annealed takes about 85 MJ of energy and emits 6.2 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
N08320 Annealed's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability very good (80/100); formability very good (72/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with N08320 Annealed
Is N08320 easy to machine?
Gummy and work-hardening like other high-Ni austenitics: use rigid setups, positive-rake sharp carbide, heavy positive feeds, low-to-moderate speeds (~20–35 m/min turning) and copious sulfochlorinated or emulsion coolant; never dwell or rub.
Can N08320 be welded?
Readily welded by GTAW/GMAW/SMAW with matching N08320 filler or over-alloyed Ni-base filler (ERNiCrMo-3); keep interpass below ~150 °C, low heat input, no preheat, and avoid post-weld sensitizing exposures — Ti stabilization protects HAZ.
Can N08320 be formed, bent or molded?
Cold forms well in the annealed condition but work-hardens rapidly, so allow 40–60% more press force than 304 and plan interstage anneals at 1010–1120 °C with rapid quench; hot work 1150–1230 °C, do not finish below ~950 °C.
What surface finishes work on N08320?
Pickle (HNO₃-HF) or grit-blast plus passivation after hot work/welding to restore the passive film; electropolishing gives the best surface for acid-service vessels — anodizing is not applicable.
N08320 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 |
|---|---|---|
| C | ≤ 0.05 | 0.03 |
| Mn | ≤ 2.5 | 1 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 21 – 23 | 22 |
| Ni | 25 – 27 | 26 |
| Mo | 4 – 6 | 5 |
| Cu | ≤ 0.4 | 0.2 |
| Ti4×C minimum (stabilization against sensitization) | ≤ 0.6 | 0.3 |
| Febalance, approx. 42–46% | balance | — |
N08320 Annealed — frequently asked
What is N08320 Annealed used for?
N08320 Annealed is typically used for sulfuric and phosphoric acid handling, chemical reactor vessels, scrubber and pollution control equipment and heat exchangers in aggressive media. In short: reducing-acid superaustenitic; ti-stabilized against HAZ sensitization; weldable high-Mo austenitic.
What is the yield strength of N08320 Annealed?
N08320 Annealed has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 81% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is N08320 Annealed easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Gummy and work-hardening like other high-Ni austenitics: use rigid setups, positive-rake sharp carbide, heavy positive feeds, low-to-moderate speeds (~20–35 m/min turning) and copious sulfochlorinated or emulsion coolant; never dwell or rub.
Can N08320 Annealed be welded?
Yes — weldability is rated very good (80/100). Readily welded by GTAW/GMAW/SMAW with matching N08320 filler or over-alloyed Ni-base filler (ERNiCrMo-3); keep interpass below ~150 °C, low heat input, no preheat, and avoid post-weld sensitizing exposures — Ti stabilization protects HAZ.
What surface finishes work on N08320 Annealed?
Pickle (HNO₃-HF) or grit-blast plus passivation after hot work/welding to restore the passive film; electropolishing gives the best surface for acid-service vessels — anodizing is not applicable.
Can N08320 Annealed be formed, bent or molded?
Cold forms well in the annealed condition but work-hardens rapidly, so allow 40–60% more press force than 304 and plan interstage anneals at 1010–1120 °C with rapid quench; hot work 1150–1230 °C, do not finish below ~950 °C.
What is the maximum service temperature of N08320 Annealed?
N08320 Annealed 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 N08320 Annealed and N08320-CD?
Annealed is the default condition — standard supply condition for plate, sheet, bar and tube in corrosive chemical process service; maximum corrosion resistance and ductility. CD: choose for fasteners, shafts and pump/valve parts needing higher strength and better dimensional tolerance than annealed bar; slightly reduced ductility and corrosion margin. Yield strength is 265 MPa in Annealed versus 550 MPa in CD.
Sources
- ASTM B620 — Ni-Fe-Cr-Mo Alloy (UNS N08320) Plate, Sheet, and Strip — ASTM International (2019)
- ASTM B621 — Ni-Fe-Cr-Mo Alloy (UNS N08320) Rod and Bar — ASTM International (2019)
- ASTM B622 — Seamless Nickel and Nickel-Alloy Pipe and Tube — ASTM International (2021)
- Carpenter 20Mo-4 Alloy Technical Data — Carpenter Technology (2020)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
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.