Stainless Steel 347 UNS S34700 is advantageous for high temperature service because of its good mechanical
Stainless Steel 347 UNS S34700 is advantageous for high temperature service because of its good mechanical properties . SS 347 also has excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800 to 1500 F. SS 347 is similar to SS 321 with respect to intergranular corrosion which is achieved through the use of columbium as a stabilizing element to maximize this feature. SS 347 can not be hardened through heat treating, but elevated properties may be obtained through cold reduction. SS 347H is a modification of SS 347 with a higher carbon content, to provide improved high temperature strength.
Composition of 347/347H tubing and pipe
Grade | 347 | 347H |
UNS Designation | S34700 | S34709 |
Carbon (C) Max. | 0.08 | 0.04–0.10 |
Manganese (Mn) Max. | 2.00 | 2.00 |
Phosphorous (P) Max. | 0.04 | 0.04 |
Sulphur (S) Max. | 0.03 | 0.03 |
Silicon (Si) Max. | 0.75 | 0.75 |
Chromium (Cr) | 17.0–20.0 | 17.0–20.0 |
Nickel (Ni) | 9.0–13.0 | 9.0–13.0 |
Molybdenum (Mo) | — | — |
Nitrogen (N) | — | — |
Iron (Fe) | Bal. | Bal. |
Other Elements | Cb+Ta=10xC-1.0 | Cb+Ta=8xC-1.0 |
SPECIFICATIONS
Stainless Steel SS 347 / 347H |
|
AISI | 347 / 347H |
UNS | S34700 / S34709 |
Werkstoff Nr. | 1.4550 / 1.4961 |
MECHANICAL & PHYSICAL PROPERTIES
Density | 8.0 g/cm3 |
Melting Point | 1454 °C (2650 °F) |
Tensile Strength | Psi – 75000 , MPa – 515 |
Yield Strength (0.2%Offset) | Psi – 30000 , MPa – 205 |
Elongation | 35 % |