347 Stainless
Atlanta Rod manufactures 347 Stainless Steel bolts, rod assemblies, studs, hex nuts, and 12- point flange bolts and nuts to your custom specifications, and we guarantee to meet your delivery schedule. At Atlanta Rod and Manufacturing Co., Inc. we strive to provide our customers with the most innovative products and quality materials in the industry.
347 stainless steel has slightly improved corrosion resistance over type 321 stainless steel in strongly oxidizing environments. Type 347 is stabilized with columbium, it is preferable for aqueous and low temperature environments due to its good resistance to intergranular attack. Both 347 and 321 offer good resistance to polythionic acid stress corrosion cracking, encountered in oil refineries. The high temperature oxidation resistance of 347 is similar to that of 304 stainless steel. Useful to 1500°F.
CHEMICALS
| Cr | Ni | Cb + Ta | C | Si | Mn | P | S | Fe | |
|---|---|---|---|---|---|---|---|---|---|
| MIN | 17 | 9 | Cb 10xc | 0.04 | – | – | – | – | |
| MAX | 19 | 13 | 1 | 0.08 | 0.75 | 2 | 0.045 | 0.03 | Balance |
MECHANICALS
| Tensile Strength, ksi | 75 |
| 0.2% Yield Strength, ksi | 30 |
| Elongation, % | 40 |
| Hardness Max, Brinell | 201 |
| Temperature, °F | 68 | 400 | 800 | 1000 | 1200 | 1350 | 1500 |
|---|---|---|---|---|---|---|---|
| Ultimate Tensile Strength, ksi | 93.3 | 73.6 | 69.5 | 63.5 | 52.3 | 39.3 | 26.4 |
| 0.2% Yield Strength, ksi | 36.5 | 36.6 | 29.7 | 27.4 | 24.5 | 22.8 | 18.6 |
Features
- Good creep strength up to 1500°F
- Maintains good corrosion resistance in applications where the temperature is between 800°F and 1500°F.
- Good resistance to intergranular corrosion in the as welded condition.
Applications
- Oil Refineries
- Fluid catalytic cracking units (FCC)
- Hanger rods
- Recuperator tube sheets, shell, supports
- Especially where temperatures exceed 550°F and resistance to sulfidation is needed
- Fired heater tubes
- Distributor trays and thermowells
- Equipment in and around reactors (good resistance to polythionic acid)
* Above data from Allegheny Ludlum Steel Corporation’s Blue Sheet and Rolled Alloys