X6CrNiMoTi17-12-2 · Ti-Stabilised 316 · PRE ~24 · AD 2000-Merkblatt W0
Titanium-stabilised 316 stainless steel — the standard 316-family specification for German, Austrian, Italian, and Central European process piping. Same 18% Cr, 10% Ni, 2% Mo chemistry and PRE ~24 as 316L (1.4404), but sensitisation resistance is achieved through titanium stabilisation rather than low carbon. Specify 1.4571 when the project PID or piping class is written to German DIN or Italian UNI conventions.
Both grades achieve the same goal — a 316-family stainless steel that resists sensitisation in the weld heat-affected zone — by different means:
Limit carbon to C ≤ 0.030% — so little carbon is available that chromium carbide cannot form at sensitisation temperatures (450–850°C).
Add titanium (Ti ≥ 5×C, typically 0.40–0.70%) — titanium has stronger affinity for carbon than chromium, so TiC forms preferentially, leaving Cr free in solution.
Corrosion performance in process service: equivalent. Choice is dictated by the engineering company's home-country convention — not by any technical advantage of one approach over the other in normal service.
| System | Designation |
|---|---|
| EN Werkstoffnummer | 1.4571 |
| EN Grade Name | X6CrNiMoTi17-12-2 |
| DIN (old) | X6CrNiMoTi 17 12 2 |
| ASTM — no direct equivalent | Closest: A403 WP316L (different stabilisation method) |
| UK/US equivalent purpose | 1.4404 (316L) — functionally equivalent, different stabilisation |
| PRE | ~24 |
| AWS Filler (GTAW) | ER316L or ER316Ti (match to base metal stabilisation) |
| Element | 1.4571 (316Ti) | 1.4404 (316L) | Note |
|---|---|---|---|
| C | ≤0.080% | ≤0.030% | 316Ti uses higher C — Ti ties it up |
| Ti | 5×C min, ≤0.70% | None | The defining difference — stabiliser |
| Cr | 16.5–18.5% | 16.5–18.5% | Same |
| Ni | 10.5–13.5% | 10.0–13.0% | Essentially same |
| Mo | 2.0–2.5% | 2.0–2.5% | Same |
| PRE | ~24 | ~24 | Identical |
| W.Nr. | Grade | PRE | Key Feature | Market |
|---|---|---|---|---|
| 1.4401 | 316 | ~24 | Standard C (≤0.070%) | Non-welded / dual-cert |
| 1.4404 ★ | 316L | ~24 | Low C (≤0.030%) | UK / NL / Scandinavia / USA |
| 1.4571 ★ | 316Ti | ~24 | Ti-stabilised (≥5×C) | Germany / Austria / Italy / CE Europe |
| 1.4432 | 316L Hi-Mo | ~26 | Mo 2.5–3.0% | Upgraded chloride service |
| 1.4435 | 316L Nuclear | ~26 | Ni 12.5–15%; FN≤1 | Nuclear / Pharma / Fatigue |
