2205 vs 316L Stainless Steel
Duplex vs austenitic — when to specify 2205 and how XRF separates families in PMI.
Key Differences
| Property | 2205 (Duplex) | 316L |
|---|---|---|
| ---------- | --------------- | ------ |
| Structure | Duplex (ferritic + austenitic) | Austenitic |
| Cr | ~22% | ~16–18% |
| Ni | ~5–6% | ~10–14% |
| Mo | ~3% | ~2–3% |
| PREN | Higher | Good |
| Weldability | Moderate | Excellent |
When to use 2205
Offshore platforms, chloride-rich process piping, and applications needing higher strength with good corrosion resistance.
When to use 316L
General chemical service, food/pharma, and weld-heavy fabrication where low carbon (L) matters.
XRF PMI
2205 shows higher Cr and lower Ni than 316L. Mo is present in both — use Cr/Ni ratio and Grade ID libraries. Specelex Ultra handles duplex libraries for oil & gas PMI programs.