347 Stainless Steel Pipe
Stellanox Steel supplies premium-grade 347 Stainless Steel Pipes, tailored for high-temperature, high-pressure, and welded applications where resistance to intergranular corrosion is critical. As a niobium (columbium) stabilized austenitic stainless steel, 347 pipes deliver superior performance in extreme environments such as chemical processing, refinery piping, power generation, and heat exchanger systems.
347 is particularly effective in post-welded structures exposed to temperatures between 427°C and 899°C, where conventional stainless steels would fail due to carbide precipitation.
What is 347 Stainless Steel Pipe?
347 Stainless Steel Pipe is an austenitic stainless steel alloy similar to 304, but stabilized with niobium (Nb) to resist sensitization—the formation of chromium carbides along grain boundaries. This stabilization allows 347 to maintain excellent corrosion resistance after welding or exposure to high temperatures for prolonged periods.
It is ideal for applications that require repeated thermal cycling and high mechanical loads under corrosive and oxidizing conditions.
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Stainless Steel |
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Carbon Steel |
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Duplex Stainless Steel |
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Super Duplex Stainless Steel |
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Alloy Steel |
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Titanium |
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Hastelloy |
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Inconel |
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Monel |
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Aluminium |
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Copper |
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Pure Nickel |
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Flanges |
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Forged Fittings |
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Valves |
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Fasteners |
Key Features of 347 Stainless Steel Pipe
- Niobium Stabilized: Excellent resistance to intergranular corrosion post-welding
- Superior High-Temperature Performance: Operates efficiently up to 870°C
- Improved Creep & Stress Rupture Resistance: Suitable for heavy-duty thermal systems
- Excellent Weldability: Eliminates the need for post-weld annealing
- Good Formability: Suitable for bending, flanging, and fabrication
- Non-Magnetic in Annealed State: Preferred for sensitive instrumentation systems
- Available in Seamless & Welded Types: Meets both strength and cost-performance needs
Specification Chart – 347 Stainless Steel Pipe
| Property | Details |
|---|---|
| Grade | 347 (UNS S34700) |
| Standards | ASTM A312, A213, A269, ASME SA312 |
| Size Range | 1/8" NB to 24" NB (DN6 to DN600) |
| Wall Thickness | SCH 5 to SCH 160 / XXS |
| Lengths | 6m, 12m, or custom |
| Pipe Types | Seamless, Welded, ERW, EFW |
| End Options | Plain End, Beveled End, Threaded End |
| Finish Types | Annealed, Pickled, Polished, Bright Annealed |
| Certifications | EN 10204 3.1 / 3.2, NACE MR0175, ISO, PED |
Chemical Composition – 347 Stainless Steel Pipe
| Element | Symbol | Composition (%) |
|---|---|---|
| Chromium | Cr | 17.0 – 19.0 |
| Nickel | Ni | 9.0 – 13.0 |
| Carbon | C | ≤ 0.08 |
| Manganese | Mn | ≤ 2.0 |
| Silicon | Si | ≤ 0.75 |
| Phosphorus | P | ≤ 0.045 |
| Sulfur | S | ≤ 0.030 |
| Niobium + Tantalum | Nb + Ta | ≥ 10x (C%) to 1.10 |
| Iron | Fe | Balance |
Mechanical Properties – 347 Stainless Steel Pipe
| Property | Value |
|---|---|
| Tensile Strength (MPa) | ≥ 515 |
| Yield Strength (MPa) | ≥ 205 |
| Elongation (%) | ≥ 40 |
| Hardness (HRB) | ≤ 95 |
| Modulus of Elasticity | 193 GPa |
| Density | 7.90 g/cm³ |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM | 347 |
| EN | 1.4550 |
| JIS | SUS 347 |
| UNS | S34700 |
| DIN | X6CrNiNb18-10 |
347 Stainless Steel Pipe Weight Chart
| OD (mm) | Wall Thickness (mm) | Weight per Meter (kg) | Weight per 6m (kg) |
|---|---|---|---|
| 21.3 | 2.77 | 1.26 | 7.56 |
| 33.4 | 3.38 | 2.61 | 15.66 |
| 42.2 | 3.56 | 3.64 | 21.84 |
| 48.3 | 3.68 | 4.46 | 26.76 |
| 60.3 | 3.91 | 6.17 | 37.02 |
| 73.0 | 5.16 | 10.14 | 60.84 |
| 88.9 | 5.49 | 13.10 | 78.60 |
| 114.3 | 6.02 | 20.40 | 122.40 |
Applications of 347 Stainless Steel Pipe
- High-temperature welded equipment
- Steam piping and exhaust manifolds
- Heat exchangers and reactor vessels
- Petrochemical refineries and pressure systems
- Thermal oxidizers and superheater tubes
- Power generation and boiler feed lines
- Flue gas scrubber systems
Benefits of 347 Stainless Steel Pipe
- Improved performance after welding without carbide precipitation
- High resistance to creep, stress rupture, and oxidation
- Durable under mechanical and thermal stress
- Maintains structural integrity under cyclic temperature loads
- Reduced downtime with long service life
- Sustainable and recyclable steel choice
2025 Stellanox Steel |