High Quality Stainless Steel Sheets & Plates
347 / 347H • Formable • Ductile • Machinable
Get a QuoteStainless Steel 347 / 347H Explained
Stainless Steel 347 and 347H are niobium-stabilized austenitic stainless steels engineered for excellent resistance to intergranular corrosion and high-temperature oxidation. The stabilization prevents chromium carbide precipitation during welding and prolonged thermal exposure. SS 347 offers superior corrosion resistance, while SS 347H, with higher carbon content, provides enhanced creep and rupture strength in continuous high-temperature service.
Commonly used in refinery systems, superheaters, high-temperature pressure vessels, petrochemical pipelines, and power generation equipment, SS 347/347H deliver exceptional structural stability under severe thermal and corrosive operating conditions.
347/347H STAINLESS STEEL SHEETS AND PLATES EQUIVALENT GRADES
| STANDARD |
|---|
| SS 347 |
| SS 347H |
SPECIFICATION OF STAINLESS STEEL 347/347H SHEETS AND PLATES
| Standard | ASTM A240 / ASME SA240 |
|---|---|
| Dimension Standard | JIS, AISI, ASTM, GB, DIN, EN, etc |
| Width | 1000mm, 1219mm, 1500mm, 1800mm, 2000mm, 2500mm, 3000mm, 3500mm, etc |
| Length | 2000mm, 2440mm, 3000mm, 5800mm, 6000mm, etc |
| Thickness | 0.3 mm to 120 mm |
| Form | Coils, Foils, Rolls, Plain Sheet, Shim Sheet, Perforated Sheet, Chequered Plate, Strip, Flats, Blank (Circle), Ring (Flange) etc. |
| Surface Finishing | Hot rolled plate (HR), Cold rolled sheet (CR), 2B, 2D, BA, NO.1, NO.4, NO.8, 8K, mirror, Chequered, embossed, hair line, sand blast, Brush, etching, SATIN (Met with Plastic Coated) etc. |
CHEMICAL COMPOSITION OF STAINLESS STEEL 347/347H SHEETS AND PLATES
| Grade | C% | Cr% | Mn% | Ni% | P% | S% | Si% | Cb/Ta% |
|---|---|---|---|---|---|---|---|---|
| 347 | 0.08 max | 17.0-20.0 | 2.0 max | 9.0-13.0 | 0.04 max | 0.030 max | 0.75 max | min:10x C max: 1.0 |
| 347H | 0.04-0.10 | 17.0-20.0 | 2.0 max | 9.0-13.0 | 0.03 max | 0.030 max | 0.75 max | min:10x C max: 1.0 |
MECHANICAL PROPERTIES OF STAINLESS STEEL 347/347H SHEETS AND PLATES
| Grade | Tensile Strength | Yield Strength | Elongation (%) | Hardness (Brinell) MAX | Hardness (Rockwell B) MAX |
|---|---|---|---|---|---|
| 347/347H | 75 ksi (515 MPa) min | 30 ksi (205 MPa) min | 40 min | 201 | 95 |
💡 Practical Difference in Use
Use Stainless Steel 347 when: excellent resistance to intergranular corrosion is required along with good weldability and oxidation resistance at elevated temperatures.
→ Example: heat exchangers, pressure vessels, expansion joints, and furnace components.
Use Stainless Steel 347H when: higher creep strength and improved performance in sustained high-temperature service are required for pressure-retaining and structural components. → Example: superheater tubes, boiler parts, high-temperature piping, and refinery heaters.
Applications of Stainless Steel 347 / 347H Sheets and Plates
Stainless Steel 347 and 347H are niobium-stabilized austenitic grades designed for high-temperature service where resistance to carbide precipitation and oxidation stability are critical.
- High-Temperature Pressure Equipment: Excellent creep resistance for prolonged elevated temperature service.
- Heat Exchangers & Furnace Parts: Reliable oxidation resistance under continuous heat exposure.
- Petrochemical Processing: Ideal for refinery heaters, cracking units, and hot process piping.
When to Choose Stainless Steel 347 vs. 347H?
The selection depends on operating temperature, pressure level, and long-term creep strength requirements.
Choose SS 347 when:
- Excellent resistance to intergranular corrosion is required
- Good weldability without post-weld heat treatment is needed
- Operating temperatures are moderate to high
- Used in cyclic heating and cooling environments
- Fabrication ease is a key requirement
- Long-term oxidation resistance is essential
Choose SS 347H when:
- Higher creep and stress rupture strength is required
- Service temperatures exceed 550°C
- Used in high-pressure and load-bearing equipment
- Superior high-temperature structural stability is critical
- Common in power generation and refinery applications
- Better resistance to thermal deformation is needed
Industries That Use Stainless Steel 347 / 347H Sheets and Plates
These grades are widely used in industries requiring strong resistance to high-temperature oxidation, intergranular corrosion, and long-term thermal stability.
Extensively used in high-temperature steam systems.
Uses
Superheaters, boiler tubes, pressure components.
Why SS 347/347H?
Excellent creep resistance and oxidation protection.
Used in high-temperature hydrocarbon processing.
Uses
Process heaters, cracking units, hot piping systems.
Why SS 347?
Prevents carbide precipitation during prolonged exposure to heat.
Reliable for heat-intensive chemical reactions.
Uses
Reactors, distillation columns, high-temperature vessels.
Why SS 347?
Maintains corrosion resistance after welding.
Used in exhaust and high-heat structural parts.
Uses
Jet engine exhaust components, aircraft ducting.
Why SS 347H?
Superior strength retention at elevated temperatures.
Used in continuous furnace operations.
Uses
Radiant tubes, furnace fixtures, heat shields.
Why SS 347H?
Designed for prolonged high-temperature service.
Critical for high-pressure and high-temperature vessels.
Uses
Pressure shells, tube sheets, and nozzle components.
Why SS 347?
Excellent weld stability and corrosion resistance.
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