Stainless Steel 1.4539
EN 1.4539 · UNS N08904 · ASTM 904L · GB 00Cr20Ni25Mo4.5Cu
1.4539 (X1NiCrMoCu25-20-5, N08904, 904L) is a low-carbon, high-nickel austenitic stainless steel with molybdenum and copper, the reference superaustenitic grade for sulfuric and phosphoric acid duty and chloride stress-corrosion cracking resistance.
Reference datasheet — 1.4539 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 AT condition
1.4539 tempers and conditions
1.4539 is supplied in 6 conditions, soft to hard. AT is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged + solution annealed (bar, flange, valve body) | Heavy sections per ASTM B649/B564-type practice; forged then re-annealed and quenched to restore corrosion resistance. | 250 | 580 | 43 | 160 HB | 1.7 % IACS |
ATDefault Solution annealed | Standard supply condition for plate, bar, pipe and fittings; maximum corrosion resistance and ductility. | 260 | 600 | 45 | 165 HB | — |
As-welded deposit | Weld-metal condition — use overalloyed Ni-base filler (e.g. ERNiCrMo-3/-13) to avoid Mo depletion in dendrite cores. | 330 | 590 | 35 | 180 HB | 1.7 % IACS |
Cold drawn | Pick for fasteners, shafts and instrument tubing needing closer tolerance and higher yield than annealed. | 480 | 720 | 28 | 19 HRC | 1.7 % IACS |
Cold worked to Rm ≥ 700 MPa | Light strain-hardened temper (≈1/4 hard) for springy sheet parts and strength-critical thin sections. | 480 | 760 | 25 | 20 HRC | 1.7 % IACS |
Cold worked to Rm ≥ 850 MPa | Half-hard strip/wire for high-strength clamps, springs and reinforcement where corrosion life still matters. | 650 | 900 | 15 | 27 HRC | 1.7 % IACS |
Supply forms, finishes and certifications
Ways 1.4539 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
WIRE-H | Cold drawn hard wire | Supply form |
1D | Hot rolled, solution annealed, pickled | Surface finish |
2B | Cold rolled, annealed, pickled, skin passed | Surface finish |
2D | Cold rolled, annealed, pickled | Surface finish |
BA | BA | Surface finish |
What is 1.4539?
1.4539 (X1NiCrMoCu25-20-5, N08904, 904L) is a low-carbon, high-nickel austenitic stainless steel with molybdenum and copper, the reference superaustenitic grade for sulfuric and phosphoric acid duty and chloride stress-corrosion cracking resistance. It is broadly stocked as 2B, 2D and BA sheet, 1D plate, cold-drawn bar, wire, tube and forgings, with annealed values near 260 MPa yield, 600 MPa tensile, 45 % elongation and 165 HB and service to 400 °C. Formability is good (78), but the alloy work hardens strongly and machines slowly; where hot-chloride pitting is more severe, step up to Alloy 31 (1.4563) or 654 SMO (1.4652). 1.4539 has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,320°C (2,408 °F). 1.4539 has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
What is 1.4539 used for?
- sulfuric acid plants
- flue gas desulfurization scrubbers
- pulp bleaching equipment
- seawater piping
- food and pharma processing
Advantages
- Forms and bends easily — 78/100, better than 90% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% 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
- Readily welded — 80/100, better than 80% 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 — 6.5 kg CO₂/kg, worse than 93% of stainless steel grades
- Low strength — 260 MPa (37.7 ksi), worse than 84% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
1.4539 properties
Typical room-temperature values for 1.4539-AT; bars are the position among stainless steel grades.
Physical3
1.4539 has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,320°C (2,408 °F).
Mechanical15
1.4539 has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4539 is rated for continuous service to 400°C (752 °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 15.8 µm/m·K (8.78 µin/in·°F).
Electrical3
1.4539 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 1.4539 takes about 88 MJ of energy and emits 6.5 kg of CO₂ — more than 93% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
1.4539's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability very good (80/100); formability very good (78/100).
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. 1.4539 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4539
Is 1.4539 easy to machine?
Machine like a high-Ni superaustenitic: rigid setup, sharp positive-rake carbide, heavy positive feed to cut under the work-hardened skin, ~30 % of 1212 speeds, flood emulsion or high-pressure coolant.
Can 1.4539 be welded?
Excellent weldability by GTAW/GMAW/SMAW with low heat input (<1.5 kJ/mm) and interpass <150 °C; use overalloyed filler (ERNiCrMo-3, ERNiCrMo-13 or 27-31-4-Cu) to offset Mo segregation; no preheat or PWHT required.
Can 1.4539 be formed, bent or molded?
Very ductile but strongly work hardening — allow 1.5–2× the press force used for carbon steel, generous bend radii, intermediate solution anneals for deep multi-stage draws; hot work 1150–900 °C then re-anneal.
1.4539 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, resists sensitisation | ≤ 0.02 | 0.01 |
| Si | ≤ 0.7 | 0.4 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.01 | 0 |
| Cr | 19 – 21 | 20 |
| Nistabilises austenite, resists reducing acids | 24 – 26 | 25 |
| Mo | 4 – 5 | 4.5 |
| Cukey for sulphuric acid resistance | 1.2 – 2 | 1.5 |
| NEN 10088 optional | ≤ 0.15 | 0.06 |
| Fe | balance |
What surface finishes work on 1.4539?
Pickle in HNO₃/HF or use paste after welding, then passivate (ASTM A967) or electropolish for maximum pitting resistance; takes a high mechanical or mirror polish; never anodise.
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 1.4539 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08904
- ASTM
- 904L
- EN / DIN / Werkstoff-Nr.
- X1NiCrMoCu25-20-5
- GB (China)
- 00Cr20Ni25Mo4.5Cu
How much does 1.4539 cost?
1.4539 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.
1.4539 — frequently asked
What is 1.4539 used for?
1.4539 is typically used for sulfuric acid plants, flue gas desulfurization scrubbers, pulp bleaching equipment, seawater piping and food and pharma processing. In short: baseline superaustenitic grade; best-stocked acid stainless; strong sulfuric acid resistance.
What is the yield strength of 1.4539?
1.4539 has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 84% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4539 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Machine like a high-Ni superaustenitic: rigid setup, sharp positive-rake carbide, heavy positive feed to cut under the work-hardened skin, ~30 % of 1212 speeds, flood emulsion or high-pressure coolant.
Can 1.4539 be welded?
Yes — weldability is rated very good (80/100). Excellent weldability by GTAW/GMAW/SMAW with low heat input (<1.5 kJ/mm) and interpass <150 °C; use overalloyed filler (ERNiCrMo-3, ERNiCrMo-13 or 27-31-4-Cu) to offset Mo segregation; no preheat or PWHT required.
What surface finishes work on 1.4539?
Pickle in HNO₃/HF or use paste after welding, then passivate (ASTM A967) or electropolish for maximum pitting resistance; takes a high mechanical or mirror polish; never anodise.
Can 1.4539 be formed, bent or molded?
Very ductile but strongly work hardening — allow 1.5–2× the press force used for carbon steel, generous bend radii, intermediate solution anneals for deep multi-stage draws; hot work 1150–900 °C then re-anneal.
What is the maximum service temperature of 1.4539?
1.4539 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4539-AT and 1.4539-C850?
AT is the default condition — standard supply condition for plate, bar, pipe and fittings; maximum corrosion resistance and ductility. C850: half-hard strip/wire for high-strength clamps, springs and reinforcement where corrosion life still matters. Yield strength is 260 MPa in AT versus 650 MPa in C850.
How much does 1.4539 cost?
1.4539 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
- EN 10088-1/-2/-3 Stainless steels — X1NiCrMoCu25-20-5 (1.4539) — CEN (2014)
- ASTM A240/A240M — plate, sheet, strip (UNS N08904) — ASTM (2023)
- ASTM B625 / B649 / B677 — N08904 plate, bar and tube — ASTM (2022)
- 904L / 1.4539 alloy datasheet — Outokumpu (2023)
- Sanicro 28 / 904L family corrosion data — Alleima (Sandvik) (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- GB/T 24511 / GB/T 4237 (00Cr20Ni25Mo4.5Cu) — SAC (2017)
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.