Stainless Steel N08024 HF-ANN
Finish state
UNS N08024 · ASTM B366/B462
HF-ANN = hot finished, annealed
Pick for large-diameter bar, forged flanges and fittings where sizes exceed cold-drawn capability.
Values for the HF-ANN condition
Other N08024 tempers and conditions
N08024 is listed in 5 conditions; see the grade overview at N08024.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HF-ANNThis page Hot finished, annealed | Pick for large-diameter bar, forged flanges and fittings where sizes exceed cold-drawn capability. | 280 | 600 | 42 | 175 HB | 1.6 % IACS |
ANNDefault Annealed | Standard supply condition for plate, sheet, tube and fittings; maximum corrosion resistance and ductility. | 290 | 620 | 45 | 180 HB | — |
Cold drawn then annealed | Cold-drawn size and finish accuracy with fully softened, corrosion-optimum microstructure. | 300 | 625 | 42 | 185 HB | 1.6 % IACS |
As-welded deposit | Property basis for weld joints in fabricated vessels; use overalloyed Ni-base filler for full corrosion matching. | 320 | 600 | 32 | 195 HB | 1.6 % IACS |
Cold worked | Choose when higher strength and hardness are needed (fasteners, shafts, springy strip); residual stress lowers SCC margin. | 590 | 790 | 22 | 25 HRC | — |
What is N08024 HF-ANN?
N08024 HF-ANN is N08024 supplied in the HF-ANN condition — pick for large-diameter bar, forged flanges and fittings where sizes exceed cold-drawn capability. N08024 HF-ANN has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 193 GPa (28 Msi). N08024 HF-ANN has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 98% of stainless steel grades. It melts at 1,370°C (2,498 °F). ANN is the default condition FabDigit quotes; HF-ANN is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Forms and bends easily — 74/100, better than 86% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
Limitations
- Low electrical conductivity — 1.6 % IACS, worse than 99% of stainless steel grades
- Poor heat conductor — 11.5 W/m·K (6.64 BTU/hr·ft·°F), worse than 97% of stainless steel grades
- High embodied carbon — 5.6 kg CO₂/kg, worse than 83% of stainless steel grades
- Low strength — 280 MPa (40.6 ksi), worse than 75% of stainless steel grades
N08024 HF-ANN properties
Typical room-temperature values for N08024 HF-ANN; 22 are specific to this condition. Other listed values are N08024 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
N08024 HF-ANN has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 98% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical14
N08024 HF-ANN has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 75% of stainless steel grades. Elongation at break is 42% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
N08024 HF-ANN is rated for continuous service to 425°C (797 °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 14.4 µm/m·K (8 µin/in·°F).
Electrical3
N08024 HF-ANN conducts electricity at 1.6 % IACS, worse than 99% 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 N08024 HF-ANN takes about 78 MJ of energy and emits 5.6 kg of CO₂ — more than 87% of stainless steel grades. Typical recycled content is 35%.
Manufacturability8
N08024 HF-ANN's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (72/100); formability very good (74/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with N08024 HF-ANN
Is N08024 easy to machine?
Machines like a high-nickel superaustenitic: rigid setups, positive-rake carbide, low speed with heavy positive feed, flood coolant and no dwell to avoid work-hardened glaze.
Can N08024 be welded?
GTAW/GMAW/SMAW with matching Nb-stabilized or overalloyed Ni-Cr-Mo filler (e.g. ERNiCrMo type), low heat input, no preheat, interpass below ~150 °C, back-purge for corrosion service.
Can N08024 be formed, bent or molded?
Very ductile but high work-hardening rate — allow extra press tonnage and springback, intermediate solution anneal (1030–1090 °C, rapid cool) for severe forming.
What surface finishes work on N08024?
Pickle and passivate after hot work or welding to restore the passive film; electropolishing gives best performance in mixed-acid service; not anodizable.
N08024 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 |
|---|---|---|
| Clow-carbon for weldability | ≤ 0.03 | 0.02 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 0.5 | 0.35 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| NiSCC and acid resistance | 35 – 40 | 37 |
| Cr | 22.5 – 25 | 23.5 |
| Moraised vs Alloy 20 for pitting resistance | 3.5 – 5 | 4.2 |
| Cusulfuric acid resistance | 0.5 – 1.5 | 1 |
| NbNb+Ta, stabilizer against sensitization | 0.15 – 0.35 | 0.25 |
| Febalance, nominally ~33 % | balance | — |
N08024 HF-ANN — frequently asked
What is N08024 HF-ANN used for?
N08024 HF-ANN is typically used for sulfuric and nitric acid handling, chemical process vessels, pump and valve components and fasteners in corrosive service. In short: mixed-acid Alloy 20 variant; nitric plus sulfuric resistance; nickel-alloy cost level.
What is the yield strength of N08024 HF-ANN?
N08024 HF-ANN has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 75% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is N08024 HF-ANN easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Machines like a high-nickel superaustenitic: rigid setups, positive-rake carbide, low speed with heavy positive feed, flood coolant and no dwell to avoid work-hardened glaze.
Can N08024 HF-ANN be welded?
Yes — weldability is rated very good (72/100). GTAW/GMAW/SMAW with matching Nb-stabilized or overalloyed Ni-Cr-Mo filler (e.g. ERNiCrMo type), low heat input, no preheat, interpass below ~150 °C, back-purge for corrosion service.
What surface finishes work on N08024 HF-ANN?
Pickle and passivate after hot work or welding to restore the passive film; electropolishing gives best performance in mixed-acid service; not anodizable.
Can N08024 HF-ANN be formed, bent or molded?
Very ductile but high work-hardening rate — allow extra press tonnage and springback, intermediate solution anneal (1030–1090 °C, rapid cool) for severe forming.
What is the maximum service temperature of N08024 HF-ANN?
N08024 HF-ANN is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between N08024-ANN and N08024-CW?
ANN is the default condition — standard supply condition for plate, sheet, tube and fittings; maximum corrosion resistance and ductility. CW: choose when higher strength and hardness are needed (fasteners, shafts, springy strip); residual stress lowers SCC margin. Yield strength is 290 MPa in ANN versus 590 MPa in CW.
Sources
- ASTM B463 — UNS N08020/N08024/N08026 Plate, Sheet, and Strip — ASTM International (2020)
- ASTM B473 — UNS N08020/N08024/N08026 Bar and Wire — ASTM International (2019)
- ASTM B462 / B366 — Forged or Rolled Flanges and Factory-Made Fittings — ASTM International (2021)
- 20Mo-4 Alloy (UNS N08024) technical data — Carpenter Technology (2020)
- ASM Handbook Vol.13B — Corrosion: Materials (superaustenitic stainless steels) — ASM International (2005)
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.