Physical properties
| Density | 8.0 | g/cm³ |
| Modulus E | 190 / 184 / 177 / 170 / 164 / 158 | GPa @ 20 / 100 / 200 / 300 / 400 / 500 °C |
| Thermal conductivity | 8.6 | W/(m·K) @ 20 °C |
| Thermal expansion | 15.0 / 15.4 / 15.8 / 16.2 / 16.4 | 10⁻⁶/K, mean 20-100 / 20-200 / 20-300 / 20-400 / 20-500 °C |
| Specific heat | 500 | J/(kg·K) @ 20 °C |
| Resistivity | 0.78 | Ω·mm²/m @ 20 °C |
Informative values: they vary with composition, condition and test method. Use the governing standard or measured mill data for pressure and heat-transfer calculations.
Values are taken from EN 1.4652 (the same alloy) and are informative.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements7 elements | |||
| Fe | Iron | Bal. | |
| Cr | Chromium | 24 – 25% | |
| Ni | Nickel | 21 – 23% | |
| Mo | Molybdenum | 7 – 8% | |
| Mn | Manganese | 2 – 4% | |
| N | Nitrogen | 0.45 – 0.55% | |
| Cu | Copper | 0.3 – 0.6% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual4 elements | |||
| Si | Silicon | ≤ 0.5% | |
| C | Carbon | ≤ 0.02% | |
| P | Phosphorus | ≤ 0.03% | |
| S | Sulphur | ≤ 0.005% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Bar and shapes | Annealed | ≥ 750 (109 ksi) | ≥ 430 (62 ksi) | ≥ 40 | Also specified: Reduction of area Z ≥ 40 % · Hardness ≤ 250 HBW |
| Bars (EN 10088-3, ≤50 mm) | +AT (solution annealed) | 750 – 1000 | ≥ 430 | ≥ 40 | Also specified: Hardness ≤ 310 HBW Rp1.0 ≥ 470 MPa; KV ≥ 100 J longitudinal. |
| Plate, sheet and strip | |||||
| Plate, sheet and strip | Standard heat-treated delivery condition | ≥ 750 (109 ksi) | ≥ 430 (62 ksi) | ≥ 40 | Also specified: Hardness ≤ 250 HBW |
| Sheet, strip and plate (EN 10088-2: cold strip ≤8, hot strip ≤13.5, plate ≤15 mm) | +AT (solution annealed) | 750 – 1000 | ≥ 430 | ≥ 40 | Rp1.0 ≥ 470 MPa; KV ≥ 100/60 J (long./transv., over 10 mm). |
Where this grade is recommended
Matched in 3 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Desalination & RO | Marine & Offshore | ≤ 45 °C | 2 / 12 | 93 |
| High-velocity seawater | Marine & Offshore | 40 – 90 °C | 3 / 9 | 89 |
| Flue-gas desulphurisation | Environmental & FGD | ≤ 80 °C | 5 / 11 | 89 |
Designations & equivalents
| W.Nr. (Germany) | 1.4652 |
| EN designation | X1CrNiMoCuN24-22-8 |
| Trade name(s) | 654 SMO |
| ASTM / AISI | A240 / A479 |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
4 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is 654 SMO · UNS S32654?
654 SMO · UNS S32654 — Super-austenitic stainless. 7Mo top-tier austenitic (PREN ≈ 56) — desalination and bleach under extreme chlorides
What is the maximum service temperature of S32654?
Typically about 400 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of S32654?
The specified minimum tensile strength is 750 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover S32654?
ASTM A240/A240M-26, ASTM A479/A479M-25, EN 10088-2 (sheet, plate, strip), EN 10088-3 (bar, rod, wire, sections)
Where is S32654 typically used?
Desalination & RO (Marine & Offshore); High-velocity seawater (Marine & Offshore); Flue-gas desulphurisation (Environmental & FGD)
In which forms is S32654 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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