ASTM A789 Duplex Stainless Steel Pipe
ASTM A789 Duplex Stainless Steel Pipe
ASTM A789 duplex stainless steel pipe specifications
Chemical Composition
| Grade | Typical Chemical Composition (%) | Phase Ratio |
|---|---|---|
| UNS S31803 | Cr:22, Ni:5.5, Mo:3, N:0.14 | Austenite ≈50% + Ferrite ≈50% |
| UNS S32750 | Cr:25, Ni:7, Mo:4, N:0.27 | Austenite ≈40% + Ferrite ≈60% |
Mechanical Properties
| Property | Requirements | Test Standard |
|---|---|---|
| Yield Strength (MPa) | ≥450 (S31803) / ≥550 (S32750) | ASTM E8/E8M |
| Tensile Strength (MPa) | ≥620 (S31803) / ≥795 (S32750) | ASTM E8/E8M |
| Elongation (%) | ≥25 | ASTM E8/E8M |
ASTM A789 vs ASTM A790Duplex Stainless Steel Pipe
| Standard | Scope | Special Requirements |
|---|---|---|
| ASTM A789 | General-purpose seamless/welded duplex steel pipes. | - Direct use after cold working (no annealing required). |
| ASTM A790 | Super duplex steel pipes (e.g., S32750). | - Higher PREN (Pitting Resistance Equivalent Number) and impact toughness. |
| EN 10216-5 | European standard for pressure applications. | - More stringent low-temperature impact testing requirements. |
