Alloy SteelOthers
Description (English)
254 SMO stub end is a pipe fitting made from 254 SMO, a high-alloy super-austenitic stainless steel (also known as 6Mo super-austenitic). It is designed for use with lap joint flanges in piping systems requiring exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in severe chloride environments.
Size Range
- 1/2" (DN15) – 24" (DN600)
Grade Specification
| System | Value |
|---|---|
| 🇺🇸 UNS | S31254 |
| ASTM / ASME | A182 F44 (forgings), A312 TP31254 (pipe), A403 WP31254 (fittings) |
| 🇪🇺 EN | 1.4547 (X1CrNiMoCuN20-18-7) |
| 🇪🇺 EN | 1.4547 |
| 🇯🇵 JIS | SUS31254 |
| 🇨🇳 GB | 015Cr21Ni26Mo5Cu2 (S31254) |
Chemical Composition
| Element | Value |
|---|---|
| C | ≤ 0.020 |
| Si | ≤ 0.80 |
| Mn | ≤ 1.00 |
| P | ≤ 0.030 |
| S | ≤ 0.010 |
| Cr | 19.5 – 20.5 |
| Ni | 17.5 – 18.5 |
| Mo | 6.0 – 6.5 |
| Cu | 0.50 – 1.00 |
| N | 0.18 – 0.22 |
| Fe | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength Rm | ≥ 650 MPa |
| Yield Strength Rp0.2 | ≥ 300 MPa |
| Elongation A (50mm) | ≥ 35% |
| Reduction in Area | - |
| Hardness | ≤ 210 HB |
| Impact KV2 (room temp) | - |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | - | 8.00 g/cm³ |
| Melting Point Range | - | 1,320 – 1,390 °C |
| Modulus of Elasticity | - | 195 GPa |
| Shear Modulus | - | 74 GPa |
| Poisson's Ratio | - | 0.30 |
| Thermal Conductivity (20°C) | - | 14 W/(m·K) |
| CTE (20–100°C) | - | 16.5 ppm/°C |
| Specific Heat (20°C) | - | 0.50 kJ/(kg·K) |
| Electrical Resistivity (20°C) | - | 0.85 μΩ·m |
| Magnetism | - | Non-magnetic (fully austenitic) |
Applications
- Seawater Systems
- Oil & Gas / Offshore
- Chemical Processing
- Power Generation
- Desalination
- Pulp & Paper
- Pharmaceutical
- Food / Beverage
- Marine