321 / 347
Titanium and niobium stabilised austenitic grades. The stabilising addition ties up carbon so the steel resists intergranular corrosion after prolonged exposure in the 425-815 C sensitisation range.
- Stabilised against sensitisation
- Superior elevated temperature creep strength
Available forms & sizes
| Form | Size range |
|---|---|
| Plates | 1.5 - 100 mm thk, up to 2500 mm wide |
| Seamless Pipes & Tubes | 1/2" - 24" NB, SCH 5S - SCH 160 |
| Round Bars | 6 - 500 mm dia |
| Flanges | 1/2" - 48", 150# - 2500# |
| Fittings | 1/2" - 48", SCH 10S - SCH 160 |
Chemical composition (%)
| Element | Min | Max |
|---|---|---|
| C | - | 0.08 |
| Cr | 17.0 | 19.0 |
| Ni | 9.0 | 12.0 |
| Ti / Nb | 5xC | - |
Mechanical properties
| Property | Value | Unit |
|---|---|---|
| Yield Strength (0.2%) | 205 min | MPa |
| Tensile Strength | 515 min | MPa |
| Elongation | 40 min | % |
Physical properties
| Property | Value | Unit |
|---|---|---|
| Density | 7.92 | g/cm3 |
| Max Service Temperature | 900 | C |
Typical applications
Other grades in Stainless Steel
304 / 304L
The workhorse austenitic stainless steel. 304L's lower carbon content prevents carbide precipitation during welding, making it the default choice for welded fabrications that cannot be post-weld annealed.
316 / 316L
Molybdenum-bearing austenitic stainless steel. The 2-3% Mo addition transforms pitting resistance in chloride-bearing media, making 316L the baseline grade for marine and chemical service in the Gulf.
904L
High alloy austenitic grade with 4-5% molybdenum and copper, bridging the gap between 316L and nickel alloys for sulphuric and phosphoric acid service.