347 is a niobium-containing austenitic stainless steel, while 347H is its high carbon version. In terms of composition, 347 can be seen as an alloy derived from adding niobium to the base of 304 stainless steel. Niobium is a rare earth element that functions similarly to titanium. When added to the alloy, it can refine grain structure, resist intergranular corrosion, and promote age hardening.
Ⅰ.Corresponding to national standards
| China | GBIT 20878-2007 | 06Cr18Ni11Nb | 07Cr18Ni11Nb(1Cr19Ni11Nb) |
| US | ASTM A240-15a | S34700，347 | S34709，347H |
| JIS | J1S G 4304:2005 | SUS 347 | - |
| DIN | EN 10088-1-2005 | X6CrNiNb18-10 1.4550 | X7CrNiNb18-10 1.4912 |
Ⅱ.CHEMICAL COMPOSITION OF S34700 Stainless steel bar
| Grade | C | Mn | Si | S | P | Fe | Ni | Cr |
| 347 | 0.08 max | 2.00max | 1.0 max | 0.030max | 0.045 max | 62.74 min | 9-12max | 17.00-19.00 |
| 347H | 0.04 – 0.10 | 2.0 max | 1.0 max | 0.030 max | 0.045 max | 63.72 min | 9-12max | 17.00 – 19.00 |
Ⅲ.347 347H Stainless steel bar Mechanical Properties
| Density | Melting Point | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min |
| 8.0 g/cm3 | 1454 °C (2650 °F) | Psi – 75000 , MPa – 515 |
Psi – 30000 , MPa – 205 |
40 |
Ⅳ.Material properties
①Excellent corrosion resistance comparable to 304 stainless steel.
② Between 427~816℃, it can inhibit the formation of chromium carbide, resist sensitization, and has good resistance to intergranular corrosion.
③It still has a certain creep resistance in a strong oxidizing environment with a high temperature of 816℃.
④Easy to extend and form, easy to weld.
⑤Good low temperature toughness.
Ⅴ.Application occasions
The high-temperature performance of 347&347H stainless steel is better than that of 304 and 321. It is widely used in aviation, petrochemical, food, paper and other industries, such as exhaust main pipes and branch pipes of aircraft engines, hot gas pipes of turbine compressors, and in small loads and temperatures not exceeding 850°C. Parts that work under the conditions, etc.
Post time: May-11-2024