- Description
347 Stainless Steel Round Bar: Stabilized Austenitic Grade for High-Temperature Corrosion Resistance
347 stainless steel round bar is a columbium (niobium)-stabilized austenitic stainless steel designed to resist intergranular corrosion in high-temperature environments. It is widely used in applications where welding, heat exposure, and long-term structural stability are required at the same time.
Compared with standard 304 or 316 stainless steels, 347 stainless steel provides improved resistance to carbide precipitation, making it particularly suitable for welded components exposed to temperatures between 800°F and 1500°F (427°C–816°C).
Chemical Composition of 347 Stainless Steel
The key feature of 347 stainless steel is the addition of niobium (columbium), which stabilizes carbon and prevents chromium carbide formation during welding or high-temperature service.
| Element | Typical Content (%) | Function |
|---|---|---|
| Chromium (Cr) | 17.0 – 19.0 | Corrosion and oxidation resistance |
| Nickel (Ni) | 9.0 – 13.0 | Austenitic stability and toughness |
| Niobium (Nb) | ≥ 10 × C content | Stabilizes carbon, prevents sensitization |
| Carbon (C) | ≤ 0.08 | Controlled for weldability |
| Manganese (Mn) | ≤ 2.0 | Structural stability |
| Silicon (Si) | ≤ 1.0 | Oxidation resistance improvement |
| Iron (Fe) | Balance | Base matrix |
Key Performance Advantages of 347 Stainless Steel Round Bar
347 stainless steel is designed for environments where both heat and welding are unavoidable. Its niobium stabilization provides a strong advantage in preventing intergranular corrosion after welding.
- Excellent resistance to intergranular corrosion after welding
- Stable performance in high-temperature service conditions
- Good oxidation resistance up to ~870°C–900°C
- Strong mechanical stability under thermal cycling
- Suitable for continuous and intermittent heat exposure
Industrial Applications of 347 Stainless Steel Round Bar
347 stainless steel round bar is widely used in industries requiring long-term exposure to heat and corrosive environments, especially where welded structures are unavoidable.
- Heat exchangers and boiler components
- Furnace parts and high-temperature supports
- Chemical processing equipment
- Petrochemical refinery piping systems
- Exhaust manifolds and high-temperature engine components
- Power generation and thermal processing systems
In large-scale engineering supply chains, companies like Teda Ganghua provide stabilized stainless steel bars with controlled chemistry and precise dimensional tolerance to support industrial fabrication requirements.
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Comparison with Related Stainless Steel Grades
| Grade | Key Feature | Weld Performance | Typical Application |
|---|---|---|---|
| 304 | General corrosion resistance | Good | Food equipment, structures |
| 321 | Titanium-stabilized | Good | High-temperature welded parts |
| 347 | Niobium-stabilized | Excellent | Severe weld + heat environments |
Fabrication and Machining Notes
347 stainless steel round bar is more stable in welded conditions, but it still requires controlled fabrication techniques due to its austenitic structure.
- Use low-to-medium cutting speeds to avoid work hardening
- Carbide tools are recommended for machining
- Avoid overheating during welding and grinding
- Ensure proper shielding gas during welding processes
Teda Ganghua Supply Capability for 347 Stainless Steel
Teda Ganghua supplies industrial-grade stainless steel round bars including stabilized grades such as 347, supporting global customers in petrochemical, energy, and heat-processing industries.
- Controlled chemical composition for stable performance
- Multiple diameter options and custom cutting services
- Export packaging for industrial shipments
- OEM support for engineering projects
FAQ
1. What is 347 stainless steel round bar used for?
It is mainly used in high-temperature welded applications such as heat exchangers, boilers, and chemical processing systems.
2. What makes 347 stainless steel different from 304?
347 contains niobium stabilization, which prevents carbide precipitation and improves resistance to intergranular corrosion after welding.
3. Can 347 stainless steel handle high temperatures?
Yes, it performs well in continuous service up to around 870°C–900°C depending on environment.
4. Is 347 stainless steel good for welding?
Yes, it is specifically designed for welded structures and maintains corrosion resistance after welding.
5. Does Teda Ganghua supply 347 stainless steel round bars?
Yes, Teda Ganghua provides stabilized stainless steel round bars with industrial-grade quality control and export-ready supply.
