Alloy 31 (UNS N08031)
Alloy 31 (UNS N08031, W.Nr. 1.4562) carries about 27% chromium, 31% nickel, 6.5% molybdenum and a nitrogen addition — a combination that gives it exceptional resistance to hot sulphuric and phosphoric acid as well as to chloride pitting. It is used in acid plant, flue-gas cleaning, seawater systems and pickling lines where lower-alloyed grades corrode away.
Available Forms
Specification Overview
| Supplier & Manufacturer | Aurico Alloys LLP |
|---|---|
| Grade | Alloy 31 (UNS N08031, W.Nr. 1.4562) |
| Standards | UNS N08031, EN 1.4562. Specifications differ by product form — see the individual form pages. |
| Forms Available | Sheet, plate, round bar, foil, coil, strip |
| Certification | Mill test certificates (EN 10204 3.1), RoHS and REACH compliant, full traceability |
| Price | INR 3,000 – 6,000 per kg. Indicative USD 35 – 71 per kg; quoted against grade, form, size and quantity. |
Specifications by Product Form
Alloy 31 (N08031) is supplied to a different standard in each form. Quote the one that matches the product you are ordering.
| Product form | Specification |
|---|---|
| Plate, sheet and strip | ASTM B625 |
| Rod and bar | ASTM B581 / B649 |
| Wire | ASTM B649 |
UNS & Equivalent Grades
| Property | Value |
|---|---|
| UNS number | N08031 |
| Werkstoff / EN number | 1.4562 |
| EN designation | X1NiCrMoCu32-28-7 |
| Density | 8.05 g/cm3 |
| Melting range | 1330-1370 °C |
| Modulus of elasticity (20 °C) | 198 GPa |
| Thermal conductivity (20 °C) | 11.7 W/m·K |
| Electrical resistivity (20 °C) | 104 µΩ·cm |
| Coefficient of expansion (100 °C) | 14.3 µm/m·°C |
| Magnetic permeability (relative - at 20 °C) | 1.001 |
Identifiers and physical constants for Alloy 31. A dash means no such designation is published for this grade.
How Alloy 31 Compares
| Alloy | UNS / EN | How it differs |
|---|---|---|
| Alloy 31 (Nicrofer 3127 hMo) | N08031 / 1.4562 | 6–7% molybdenum with 0.15–0.25% nitrogen on a 26–28% chromium base — the most pitting- and crevice-resistant of the four, and the one specified for hot sulphuric and phosphoric acid. |
| Alloy 28 (Sanicro 28) | N08028 / 1.4563 | Similar chromium and nickel but 3.5% molybdenum against Alloy 31’s 6–7%. Long-established in phosphoric acid and sour-gas service, and the cheaper choice where that lower molybdenum is enough. |
| 904L | N08904 / 1.4539 | The 4% molybdenum grade a step below both. Good in dilute sulphuric acid; outmatched by either alloy above in chloride-bearing media. |
| 316L | S31603 / 1.4404 | Conventional austenitic stainless, listed for context. General-purpose corrosion resistance, and the grade these alloys are specified in place of when it pits. |
Molybdenum, chromium and nitrogen figures for Alloy 31 and Alloy 28 are from the mill data cited in the table above. Grade selection depends on the specific medium, temperature and concentration — talk to us before specifying.
Chemical composition, mechanical properties and size ranges differ by product form — see the individual form pages above for the figures that apply to what you are ordering.
Aurico Alloys LLP stocks Alloy 31 across the forms above, with material test certificates (EN 10204 3.1) and export-ready packaging from Mumbai, India. Contact us for stock availability and pricing.