Characteristics
Alloy 309S (UNS S30908) stainless steel coil is austenitic chromium-nickel stainless steel that provides excellent corrosion resistance and heat resistance for many important applications. Its high chromium and nickel content provides comparable corrosion resistance, superior resistance to oxidation, and the retention of a larger fraction of room temperature strength than the common austenitic Alloy 304.
309S stainless steel coils have good weldability and can be used in the as-welded condition in construction, fabrication, and manufacturing applications. It has good resistance to pitting, crevice corrosion and stress corrosion cracking. 309S is used in many high temperature applications where the presence of Mo and Si make it resistant to sulfide stress cracking.
Chemical Analysis Weight %
(all values are maximum unless a range is otherwise indicated)
| Element | 309 | 309S | 309H |
| Chromium | 22.0 min.-24.0 max. | 22.0 min.-24.0 max. | 22.0 min.-24.0 max. |
| Nickel | 12.0 min.-15.0 max. | 12.0 min.-15.0 max. | 12.0 min.-15.0 max. |
| Carbon | 0.20 | 0.08 | 0.04 min.-0.10 max. |
| Manganese | 2.00 | 2.00 | 2.00 |
| Phosphorus | 0.045 | 0.045 | 0.045 |
| Sulfer | 0.030 | 0.030 | 0.030 |
| Silicon | 0.75 | 0.75 | 0.75 |
| Iron | Balance | Balance | Balance |
Mechanical Properties
| Properties | Metric | Imperial |
| Tensile strength, ultimate | 620 MPa | 89900 psi |
| Tensile strength, yield (0.2%) | 310 MPa | 45000 psi |
| Izod impact | 120 - 165 J | 88.5 - 122 ft-lb |
| Modulus of elasticity | 200 GPa | 29000 ksi |
| Shear modulus | 77 GPa | 11200 ksi |
| Poisson ratio | 0.3 | 0.3 |
| Elongation at break (in 50 mm) | 45% | 45% |
| Hardness, Brinell (converted from Rockwell B hardness) | 147 | 147 |
| Hardness, Knoop (converted from Rockwell B hardness) | 164 | 164 |
| Hardness, Rockwell B | 85 | 85 |
| Hardness, Vickers (converted from Rockwell B hardness) | 169 | 169 |
Thermal Properties
| Properties | Metric | Imperial |
| Thermal expansion co-efficient (@ 0-100°C/32-212°F) | 14.9 µm/m°C | 8.28 µin/in°F |
| Thermal conductivity (@0-100°C/32-212°F) | 15.6 W/mK | 108 BTU in/hr.ft².°F |
Applications
The stainless steel is easy to cut, form and fabricate. The stainless material will not rust or corrode and is perfect for roof repair, arts and crafts applications and work bench tops.
