Alloy 28 (UNS N08028)
Alloy 28 (UNS N08028, W.Nr. 1.4563) is a high-alloy austenitic stainless with roughly 27% chromium, 31% nickel and 3.5% molybdenum plus a copper addition. The high chromium handles oxidising conditions while the copper covers reducing acid, which is why it is specified for phosphoric and sulphuric acid service, fertiliser production and sour-gas tubing.
Key Properties
- Chromium 26.0-28.0%, well above the six-moly grades, which is what suits it to oxidising acids.
- Nickel 30.0-32.0% with molybdenum 3.0-4.0% and copper 0.70-1.50%.
- Carbon 0.020% maximum.
- Alloy 31 is the same chromium and nickel with molybdenum raised to 6-7% and nitrogen added.
Applications
- Wet-process phosphoric acid plant
- Sulphuric acid coolers and piping
- Fertiliser production equipment
- Metallurgical and pickling plant
Alloy 28 is the most widely used metallic material for evaporator tubes in wet-process phosphoric acid, and Alleima measures it at 0.03 mm/y in contaminated superphosphoric acid at 200 °C, against 0.10 for 904L. It is compared with the nickel alloys in our acid and alkali service guide.
Available Forms
Specification Overview
| Supplier & Manufacturer | Aurico Alloys LLP |
|---|---|
| Grade | Alloy 28 (Sanicro 28, UNS N08028, 1.4563) |
| Standards | UNS N08028, EN 1.4563. 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 1,500 – 3,500 per kg. Indicative USD 18 – 41 per kg; quoted against grade, form, size and quantity. |
Specifications by Product Form
Alloy 28 (N08028) 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 B709 |
| Rod and bar | EN 10088-3 / EN 10272 |
| Wire | Mill specification |
| Pipe and tube | ASTM B668 |
| Fittings | ASTM A403 |
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | N08028 |
| Werkstoff / EN number | 1.4563 |
| EN designation | X1NiCrMoCu31-27-4 |
| Density | 8.00 g/cm3 |
| Modulus of elasticity (20 °C) | 195 GPa |
| Thermal conductivity (20 °C) | 10 W/m·°C |
| Electrical resistivity (20 °C) | 0.99 µΩ·m |
| Specific heat (20 °C) | 460 J/kg·°C |
| Coefficient of expansion (30-100 °C) | 15 µm/m·°C |
| Magnetic permeability (relative) | 1.003 (datasheet prints this as an approximate value) |
Identifiers and physical constants for Alloy 28. A dash means no such designation is published for this grade.
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 28 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.