347 Stainless Steel Seamless Pipe

Our 347 stainless steel seamless pipe is an austenitic grade stabilized with niobium (columbium), which provides excellent resistance to intergranular corrosion and superior performance at elevated temperatures. Supplied in annealed and pickled condition, it is ideally suited for high-temperature and severe-service industrial applications.

347 Stainless Steel Seamless Pipe

Brief Introduction

347 is a niobium-stabilized austenitic stainless steel. Niobium is added to prevent chromium carbide precipitation during high-temperature exposure, which effectively avoids intergranular corrosion. It retains good creep resistance and oxidation resistance at elevated temperatures. The seamless pipe is manufactured by piercing and hot/cold drawing without welding seams, delivering superior structural integrity compared with welded tubes. It is widely used for high-temperature service environments.

Chemical Composition (wt%, ASTM A312)

Note: Niobium content shall be at least 10 times the carbon content, up to maximum 1.00%.

Mechanical Properties (ASTM A312, Solution Annealed)

• Tensile Strength, min: 515 MPa (75 ksi)
• Yield Strength (0.2% offset), min: 205 MPa (30 ksi)
• Elongation (2 in / 50 mm gauge length), min: 35%
• Hardness, max: HB 201 / HRB 92

Key Features

1. Excellent resistance to intergranular corrosion after exposure to 425–870°C
2. Good high-temperature creep and rupture strength
3. Stable austenitic microstructure, not hardenable by heat treatment
4. Good ductility and formability; suitable for bending, flanging and spinning
5. Seamless structure eliminates weld defect risks, ideal for pressure-bearing service

Typical Applications

• Power industry: boiler superheater tubes, reheater tubes, steam piping
• Petrochemical: high-temperature process piping, furnace tubes, heat exchangers
• Refinery equipment, catalytic cracking units
• Gas turbine exhaust components
• High-pressure vessels and piping working at continuous high temperature
• Aerospace and thermal engineering equipment

Standard References

ASTM A312, ASTM A213, ASME SA312, ASME SA213

Key Features

• Niobium Stabilized: Prevents chromium carbide precipitation
• High Temperature Resistance: Stable performance up to 800°C
• Excellent Corrosion Resistance: Resists intergranular corrosion
• Seamless Structure: No weld seam, high pressure resistance
• Annealed & Pickled: Clean and smooth surface finish
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Specifications

Applications

Widely used for high-temperature steam pipes, boiler tubes, heat exchangers, chemical processing equipment, exhaust systems and other applications requiring resistance to intergranular corrosion and elevated temperatures.

Why Choose Us

We supply 347 stainless steel seamless pipes with stable quality, competitive pricing and fast delivery. Custom diameters, wall thicknesses and lengths are available upon request. Please contact us for detailed quotations and free samples.