904L is a super-austenitic stainless steel known for its exceptional corrosion resistance, especially in aggressive environments. It contains high levels of chromium, nickel, molybdenum, and copper, making it ideal for demanding industrial applications.
Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) due to high molybdenum (4–5%) and copper (1–2%) content.
Performs exceptionally well in sulfuric acid, phosphoric acid, chloride-rich, and seawater environments (better than 316L or 317L).
Resistant to organic acids, acidic chlorides, and reducing chemicals.
Maintains integrity in dilute sulfuric acid (<10%) and other aggressive media where standard stainless steels (304/316) fail.
Used in chemical processing, oil & gas, and marine applications.
High tensile strength (~490 MPa) and elongation (~35%), providing durability under stress.
Maintains toughness even at cryogenic temperatures.
Can be welded using standard methods (TIG, MIG, SAW) but may require post-weld annealing for optimal corrosion resistance.
Good formability (but work-hardens faster than 304/316, requiring more power for machining).
Reduces maintenance costs in chemical plants, desalination, and offshore oil rigs.
Resists biofouling in seawater applications.
| Property | 904L (1.4539) | 316L (1.4404) | 317L (1.4438) | Duplex 2205 |
|---|---|---|---|---|
| Cr / Ni / Mo / Cu | 20% / 25% / 4.5% / 1.5% | 16.5% / 10% / 2.1% / – | 18.5% / 13.5% / 3.1% / – | 22% / 5.5% / 3% / – |
| PREN (Pitting Resistance) | ≥38 | ≥26 | ≥30 | ≥35 |
| Max Temp (Oxidizing) | 400°C (750°F) | 870°C (1600°F) | 870°C (1600°F) | 300°C (570°F) |
| Best For | Acids, chlorides, seawater | General corrosion | Better chlorides | High strength + corrosion |
Chemical & Petrochemical: Reactors, piping, heat exchangers.
Oil & Gas: Offshore platforms, seawater cooling systems.
Pharmaceutical: Equipment handling corrosive media.
Pollution Control: Flue gas desulfurization (FGD) systems.
Marine: Propeller shafts, pumps, valves.
Cherry
Website: www.jinyoumetal.com
Email: Cherry@jinyoumetal.com
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