Duplex & super duplex stainless cast steel: chemical composition
Duplex stainless cast steels solidify with a balanced ferrite–austenite microstructure, combining roughly twice the yield strength of austenitic grades such as CF8M with much better resistance to chloride stress corrosion cracking. Chromium, molybdenum and nitrogen govern pitting resistance; super duplex grades are alloyed to a PREN of at least 40. Castings are solution annealed and water quenched to restore the phase balance and avoid sigma phase.
Pump casings, impellers and valve bodies for seawater, offshore, desalination and chemical or fertilizer process service, where chlorides, acids and erosion act together.
Grades compared (mass %)
| Grade | Material no. | Standard | C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GX2CrNiMoN22-5-3 | 1.4470 | EN 10283 | ≤ 0.03 | ≤ 1.00 | ≤ 2.00 | ≤ 0.035 | ≤ 0.025 | 21.0–23.0 | 4.50–6.50 | 2.50–3.50 | – | 0.12–0.20 |
| GX2CrNiMoN26-7-4 | 1.4469 | EN 10283 | ≤ 0.03 | ≤ 1.00 | ≤ 1.00 | ≤ 0.035 | ≤ 0.025 | 25.0–27.0 | 6.00–8.00 | 3.00–5.00 | ≤ 1.30 | 0.12–0.22 |
| GX2CrNiMoCuN25-6-3-3 | 1.4517 | EN 10283 | ≤ 0.03 | ≤ 1.00 | ≤ 1.50 | ≤ 0.035 | ≤ 0.025 | 24.5–26.5 | 5.00–7.00 | 2.50–3.50 | 2.75–3.50 | 0.12–0.22 |
| CD4MCu | UNS J93370 | ASTM A890 Grade 1A | ≤ 0.04 | ≤ 1.00 | ≤ 1.00 | ≤ 0.04 | ≤ 0.04 | 24.5–26.5 | 4.75–6.00 | 1.75–2.25 | 2.75–3.25 | – |
| CD4MCuN | UNS J93372 | ASTM A890 Grade 1B | ≤ 0.04 | ≤ 1.00 | ≤ 1.00 | ≤ 0.04 | ≤ 0.04 | 24.5–26.5 | 4.70–6.00 | 1.70–2.30 | 2.70–3.30 | 0.10–0.25 |
| CD3MCuN | UNS J93373 | ASTM A890 Grade 1C | ≤ 0.03 | ≤ 1.10 | ≤ 1.20 | ≤ 0.03 | ≤ 0.03 | 24.0–26.7 | 5.60–6.70 | 2.90–3.80 | 1.40–1.90 | 0.22–0.33 |
| CD3MN | UNS J92205 | ASTM A890 Grade 4A | ≤ 0.03 | ≤ 1.00 | ≤ 1.50 | ≤ 0.04 | ≤ 0.02 | 21.0–23.5 | 4.50–6.50 | 2.50–3.50 | ≤ 1.00 | 0.10–0.30 |
| CE3MN | UNS J93404 | ASTM A890 Grade 5A | ≤ 0.03 | ≤ 1.00 | ≤ 1.50 | ≤ 0.04 | ≤ 0.04 | 24.0–26.0 | 6.00–8.00 | 4.00–5.00 | – | 0.10–0.30 |
| CD3MWCuN | UNS J93380 | ASTM A890 Grade 6A | ≤ 0.03 | ≤ 1.00 | ≤ 1.00 | ≤ 0.03 | ≤ 0.025 | 24.0–26.0 | 6.50–8.50 | 3.00–4.00 | 0.50–1.00 | 0.20–0.30 |
Duplex & super duplex stainless cast steel: cast and machined in-house
Tsitouras Foundry casts duplex and super duplex pump casings, impellers and process components, with heat treatment, 3D-printed sand cores for complex passages, CNC machining and dynamic balancing in the group's own shops. Every heat is analysed by OES and supplied with an EN 10204 3.1 certificate.
- Sand casting at our foundry in Mandra, Attica; centrifugal casting for bushings, sleeves and liners
- Heat treatment at the foundry (water, oil or air quench); CNC machining in our machine shop in Perama
- Spectrometer analysis of every heat, mechanical testing and NDT
- EN 10204 3.1 inspection certificates; ISO 9001 (both plants) and ISO 14001 (foundry) certified
All alloy families
For information only, without warranty: limits per the cited standard or, where stated, typical or house values; ≈ marks a comparable grade, not an equivalent. The current edition of the standard, the purchase order and the drawing govern.