Stainless Steel N08024
UNS N08024 · ASTM B366/B462
N08024 is a superaustenitic Fe-Ni-Cr-Mo stainless — a modified Alloy 20 (20Cb-3) with added molybdenum and niobium for resistance to mixed nitric and sulfuric acids — supplied to ASTM B366/B462 in annealed, hot-finished annealed, cold-drawn annealed, cold-worked and as-welded conditions.
Reference datasheet — N08024 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
N08024 tempers and conditions
N08024 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
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?
N08024 is a superaustenitic Fe-Ni-Cr-Mo stainless — a modified Alloy 20 (20Cb-3) with added molybdenum and niobium for resistance to mixed nitric and sulfuric acids — supplied to ASTM B366/B462 in annealed, hot-finished annealed, cold-drawn annealed, cold-worked and as-welded conditions. It is chosen for chemical process equipment where 316L pits or suffers weld-line attack; default properties are 290 MPa yield, 620 MPa tensile, 45 % elongation and 180 HB (87 HRB) with formability rated 75 and corrosion resistance 78. Service is limited to about 425 °C, the alloy work-hardens rapidly, and cost and availability sit closer to nickel alloys. Alloy 20 (N08020) is the cheaper alternative; N08026 carries more molybdenum. N08024 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). N08024 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi).
What is N08024 used for?
- sulfuric and nitric acid handling
- chemical process vessels
- pump and valve components
- fasteners in corrosive service
Advantages
- Forms and bends easily — 75/100, better than 87% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Good corrosion resistance — 78/100, better than 84% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% 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
N08024 properties
Typical room-temperature values for N08024-ANN; bars are the position among stainless steel grades.
Physical3
N08024 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 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 72% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
N08024 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 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 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's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability very good (72/100); formability very good (75/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. N08024 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with N08024
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.
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 |
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.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel N08024 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B366/B462
- Other
- Carpenter 20Mo-4
How much does N08024 cost?
N08024 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
N08024 — frequently asked
What is N08024 used for?
N08024 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?
N08024 has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 72% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is N08024 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 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?
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 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?
N08024 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.
How much does N08024 cost?
N08024 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.