UNS S39277 Round Bars, UNS S39277 Rods, UNS S39277 Bar

Product Description

UNS S39277 designates an elite, nitrogen-alloyed Super Duplex Stainless Steelcommercially recognized under standard forging specifications like ASTM A182 Grade F57.

Engineered specifically for extreme marine, highly acidic, and deep-sea environments, UNS S39277 round bars, rods, and bar stocks provide a distinct performance profile by combining the crack resistance of ferritic stainless steel with the high corrosion immunity of austenitic steel.

1. Material Chemistry & High-PREN Engineering

The outstanding characteristic of S39277 is its high Pitting Resistance Equivalent Number (PREN), which routinely exceeds 40. This baseline confirms its immunity to localized pitting and crevice corrosion in warm chloridic waters.

The chemistry features localized fortification from Tungsten (W) and Copper (Cu) to combat non-oxidizing acids like sulfuric and hydrochloric solutions.

Nominal Chemical Composition (%)

2. Supply Configurations & Dimensional Profiles

When purchasing or designing parts with UNS S39277 Bar and Rod stock, the material is structured to meet rigorous offshore and pressure-vessel code frameworks:

• Condition of Supply: Typically supplied in the Solution Annealed and Quenched state. This processing locks in the balanced 50/50 austenite-ferrite microstructure and ensures maximum ductility and corrosion limits.

• Size Configurations: Round bars and rods span from small cold-drawn precision lines starting at 6 mm (0.23") up to heavy forged structural rounds reaching 1200 mm (47") for major industrial components.

• Surface Finishes: Available as black (hot-rolled/forged), centerless turned, peeled, or polished bright bars depending on target machining tolerances.

• End Finishes: Readily provided with clean band-saw cut, sheared, or water-jet cut square faces.

3. High Mechanical Milestones

Because it is a Super Duplex alloy, UNS S39277 delivers roughly double the yield strength of standard 300-series austenitic stainless steels (like 316L) while offering excellent structural savings through reduced wall thicknesses.

Mechanical Benchmarks (Annealed State)

• Ultimate Tensile Strength (UTS): 118 ksi [820 MPa] minimum

• Yield Strength (0.2% Offset): 85 ksi [585 MPa] minimum

• Elongation (in 50mm): 25% minimum

• Structural Toughness: Retains high impact fracture toughness down to sub-zero temperatures ($-50^\circ\text{C}$).

4. Key Strategic Applications

UNS S39277 bar stock is used for high-integrity components operating under severe chemical or hydraulic stress:

• Offshore Oil & Gas Drivetrains: Subsea manifold piping fasteners, downhole well-tool shafts, valve internals, and specialized marine pumps.

• Desalination & Chemical Plants: High-pressure reverse osmosis pump components, heat exchanger tube-sheet bars, and chemical agitators.

• Flue Gas Desulfurization (FGD): Absorber tower shafting and internal industrial mixing rods subjected to aggressive high-sulfur scrubbing acids.