347 Stainless Steel Bar
Stellanox Steel offers corrosion-resistant, high-temperature 347 Stainless Steel Bars, specifically designed for use in welded structures and extreme thermal conditions. Stabilized with niobium (columbium), 347 bars resist intergranular corrosion even after repeated welding and heating cycles. These bars are ideal for chemical processing, aerospace, boiler manufacturing, and exhaust system components.
Available in round, square, flat, and hexagonal shapes, 347 bars deliver durability, structural integrity, and long service life in pressure and heat-intensive environments.
What is 347 Stainless Steel Bar?
347 Stainless Steel Bar is an austenitic stainless steel alloy containing chromium, nickel, and niobium (columbium) which stabilizes the steel and prevents chromium carbide formation during welding. This makes it particularly effective in environments where the metal is subjected to frequent welding and continuous high temperatures up to 870°C.
Unlike 321 (which uses titanium), 347 provides better resistance to embrittlement and intergranular attack under cyclic thermal stress, making it a preferred material for demanding applications.
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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 Bar
- Niobium-Stabilized: Prevents sensitization and weld decay.
- Superior High-Temperature Performance: Reliable in continuous use up to 870°C.
- Excellent Weldability: Suitable for heavy-duty, repeated welding applications.
- High Creep and Stress-Rupture Strength: Ideal for pressure-bearing equipment.
- Non-Magnetic (Annealed): Retains austenitic structure unless cold worked.
- Long-Term Durability: Performs well under thermal cycling and stress exposure.
Specification Chart – 347 Stainless Steel Bar
| Property | Details |
|---|---|
| Grade | 347 (UNS S34700) |
| Standards | ASTM A276, ASTM A479, EN 10088-3 |
| Sizes Available | 3 mm to 300 mm (Round/Square/Hex/Flat) |
| Length | Up to 6 meters or custom cut |
| Finishes | Black, Bright, Polished, Peeled |
| Shapes | Round, Square, Hex, Flat |
Chemical Composition – 347 Stainless Steel Bar
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 13.0 |
| Niobium (Nb) + Tantalum | ≥ 10xC – ≤ 1.0 |
| Carbon (C) | ≤ 0.08 |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
Mechanical Properties – 347 Stainless Steel Bar
| Property | Value |
|---|---|
| Tensile Strength (MPa) | ≥ 515 |
| Yield Strength (MPa) | ≥ 205 |
| Elongation (%) | ≥ 40 |
| Hardness (HRB) | ≤ 95 (Annealed) |
| Density | 7.93 g/cm³ |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM | 347 |
| EN | 1.4550 |
| JIS | SUS 347 |
| UNS | S34700 |
| DIN | X6CrNiNb18-10 |
Applications of 347 Stainless Steel Bar
- Heat Exchangers and Radiators
- Pressure Vessels and Reactors
- Welded Boiler Tubing
- Exhaust Manifolds and Turbo Casings
- Chemical and Petrochemical Processing Equipment
- Jet Engine Parts and Expansion Bellows
Benefits of 347 Stainless Steel Bar
- Stable performance in welded and thermal environments
- Prevents intergranular corrosion in heat-affected zones
- High strength and durability under stress-rupture conditions
- Easily fabricated and machined
- Performs reliably in aggressive chemical and thermal cycles
- Available in multiple shapes and finishes for industrial use
2025 Stellanox Steel |