Stainless 316L has been the workhorse of corrosion-resistant service for decades. But as projects push into more aggressive environments - chloride-rich produced water, high-pressure piping, demanding offshore exposure - designers are increasingly turning to duplex and super-duplex grades.
Duplex 2205 offers roughly twice the yield strength of 316L, which means thinner walls, lighter sections and less weld metal. Combined with significantly better chloride pitting resistance (PREN ~35 vs 24), the lifecycle math often favours duplex even at a higher per-kilo cost.
The trade-offs: tighter welding parameters, narrower service temperature window (avoid sustained service above 280°C), and a smaller pool of qualified fabricators. For projects that justify them, duplex pays back.