Nickel Alloy Alloy 31
UNS N08031 · EN 1.4562 · also Nicrofer 3127hMo
Alloy 31 (N08031, 1.4562, Nicrofer 3127hMo) is a super-austenitic Ni-Fe-Cr-Mo-Cu alloy that provides outstanding resistance to hot sulfuric and phosphoric acids together with high chloride pitting resistance, rated 92 for corrosion resistance.
Reference datasheet — Alloy 31 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 Annealed condition
Alloy 31 tempers and conditions
Alloy 31 is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault Solution Annealed (approx. 1150–1180 °C, water quenched) | Standard supply condition for plate, sheet, tube and forgings — maximum corrosion resistance and ductility. | 340 | 700 | 50 | 180 HB | — |
Cold Drawn + Solution Annealed (seamless tube, bar) | Seamless tubing and bright bar delivered in the annealed condition for acid service heat exchangers. | 350 | 700 | 48 | 185 HB | 1.7 % IACS |
As-Welded (autogenous / matching over-alloyed filler weld metal) | Joint condition of welded pipe and fabrications; use over-alloyed Ni-Cr-Mo filler to restore pitting resistance. | 380 | 680 | 35 | 200 HB | 1.7 % IACS |
Cold Worked / Strain Hardened (as-drawn, not re-annealed) | Higher-strength bar, wire and small tube where corrosion service is mild and stiffness/strength matter. | 700 | 900 | 22 | 27 HRC | 1.7 % IACS |
Supply forms, finishes and certifications
Ways Alloy 31 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ColdRolled | Cold Rolled + Solution Annealed, pickled | Surface finish |
HotFinished | Hot Finished + Solution Annealed | Surface finish |
What is Alloy 31?
Alloy 31 (N08031, 1.4562, Nicrofer 3127hMo) is a super-austenitic Ni-Fe-Cr-Mo-Cu alloy that provides outstanding resistance to hot sulfuric and phosphoric acids together with high chloride pitting resistance, rated 92 for corrosion resistance. Annealed material offers about 340 MPa yield, 700 MPa tensile, 50% elongation and 180 HB (88 HRB), with a maximum service temperature of 400 °C; typical forms are plate, sheet, cold-drawn bar and welded or seamless tube for heat exchangers. Machinability is low (rated 22) and formability moderate (65), so fabrication cost and lead time are the practical constraints. Alloy 20 is the lower-cost choice where the acid is cooler and chloride pitting is not the controlling risk. Alloy 31 has a density of 8.02 g/cm³ (0.29 lb/in³), lighter than 84% of nickel alloy grades. It melts at 1,320°C (2,408 °F). Alloy 31 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 63% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 195 GPa (28.3 Msi).
What is Alloy 31 used for?
- acid production plants
- flue gas desulfurization
- phosphoric acid evaporators
- heat exchangers
Advantages
- Low embodied carbon — 7.5 kg CO₂/kg, better than 96% of nickel alloy grades
- Good corrosion resistance — 92/100, better than 91% of nickel alloy grades
- Ductile — tolerates forming and impact — 50%, better than 88% of nickel alloy grades
- High electrical conductivity — 1.7 % IACS, better than 76% of nickel alloy grades
Limitations
- Limited service temperature — 400°C (752 °F), worse than 94% of nickel alloy grades
Alloy 31 properties
Typical room-temperature values for Alloy 31-Annealed; bars are the position among nickel alloy grades.
Physical3
Alloy 31 has a density of 8.02 g/cm³ (0.29 lb/in³), lighter than 84% of nickel alloy grades. It melts at 1,320°C (2,408 °F).
Mechanical14
Alloy 31 has a yield strength of 340 MPa (49.3 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 63% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
Alloy 31 is rated for continuous service to 400°C (752 °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 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
Alloy 31 conducts electricity at 1.7 % IACS, better than 76% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 91% of nickel alloy grades.
Sustainability4
Producing a kilogram of Alloy 31 takes about 95 MJ of energy and emits 7.5 kg of CO₂ — less than 97% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability7
Alloy 31's machinability is poor (22/100, better than 64% of nickel alloy grades); weldability very good (72/100); formability good (65/100).
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 nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Alloy 31 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Alloy 31
Is Alloy 31 easy to machine?
Very gummy and strongly work-hardening — use rigid setups, sharp positive-rake carbide, low speed (20–35 m/min) with heavy positive feed and copious flood coolant; avoid dwelling.
Can Alloy 31 be welded?
Weld with GTAW/GMAW/SMAW using over-alloyed Ni-Cr-Mo filler (e.g. ERNiCrMo-3/-4 type), low heat input, interpass <150 °C, no preheat and no PWHT required.
Can Alloy 31 be formed, bent or molded?
Cold forms readily but needs roughly twice the force of 304; hot work 1150–900 °C and always solution anneal + quench after hot forming or heavy cold work.
Alloy 31 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 intergranular corrosion resistance | ≤ 0.02 | 0.01 |
| Si | ≤ 0.3 | 0.2 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.02 | |
| S | ≤ 0.01 | |
| Cr | 26 – 28 | 27 |
| Ni | 30 – 32 | 31 |
| Mo | 6 – 7 | 6.5 |
| Cuimproves sulfuric acid resistance | 1 – 1.4 | 1.2 |
| Nraises PREN and strength | 0.15 – 0.25 | 0.2 |
| Febalance, approx. 31–33 % | balance |
What surface finishes work on Alloy 31?
Pickle and passivate after welding to remove heat tint (essential for full pitting resistance); polishes to a bright mirror finish, no anodizing applicable.
Surface treatments FabDigit runs on nickel alloy 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).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Alloy 31 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08031
- EN / DIN / Werkstoff-Nr.
- 1.4562
- Trade names
- Nicrofer 3127hMo
How much does Alloy 31 cost?
Alloy 31 is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Alloy 31 — frequently asked
What is Alloy 31 used for?
Alloy 31 is typically used for acid production plants, flue gas desulfurization, phosphoric acid evaporators and heat exchangers. In short: super-austenitic acid grade; high chloride pitting resistance; hardest of the family to machine.
What is the yield strength of Alloy 31?
Alloy 31 has a typical yield strength of 340 MPa (49.3 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 63% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is Alloy 31 easy to machine?
Not especially — machinability is rated poor (22/100, better than 64% of nickel alloy grades). Very gummy and strongly work-hardening — use rigid setups, sharp positive-rake carbide, low speed (20–35 m/min) with heavy positive feed and copious flood coolant; avoid dwelling.
Can Alloy 31 be welded?
Yes — weldability is rated very good (72/100). Weld with GTAW/GMAW/SMAW using over-alloyed Ni-Cr-Mo filler (e.g. ERNiCrMo-3/-4 type), low heat input, interpass <150 °C, no preheat and no PWHT required.
What surface finishes work on Alloy 31?
Pickle and passivate after welding to remove heat tint (essential for full pitting resistance); polishes to a bright mirror finish, no anodizing applicable.
Can Alloy 31 be formed, bent or molded?
Cold forms readily but needs roughly twice the force of 304; hot work 1150–900 °C and always solution anneal + quench after hot forming or heavy cold work.
What is the maximum service temperature of Alloy 31?
Alloy 31 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Alloy 31 cost?
Alloy 31 is a high-cost nickel alloy ($$$$), 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 B625 — UNS N08031 plate, sheet and strip — ASTM International (2022)
- EN 10088-2 / material 1.4562 (X1NiCrMoCu32-28-7) — CEN (2014)
- Nicrofer 3127 hMo — Alloy 31 material data sheet — VDM Metals (2020)
- Super-austenitic stainless steels — corrosion and physical data — Outokumpu (2021)
- ASM Handbook Vol. 13B — Corrosion: Materials — 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.