AISI 348 Stainless Steel Plate | 348 China steel mill-Direct Supply
What is AISI 348 Stainless Steel ?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 348 Stainless Steel Plate.
AISI 348 (UNS S34800) is a niobium (columbium)-stabilized austenitic stainless steel based on the 18% chromium – 10% nickel composition, with intentional restrictions on cobalt and tantalum content. Niobium is added to stabilize the grade against intergranular corrosion by forming stable niobium carbides, preventing chromium carbide precipitation during welding or exposure to the sensitization temperature range.
The controlled low cobalt content makes AISI 348 particularly suitable for nuclear applications where minimized induced radioactivity is required. It retains the good general corrosion resistance, formability, toughness and non-magnetic properties of the 347 family while meeting stricter compositional limits for specialized service.
SHH STEEL supplies AISI 348 as true China steel mill-Direct Supply, sourcing directly from major Chinese stainless steel mills. This model delivers competitive mill pricing, consistent quality, complete heat traceability and reliable delivery. SHH STEEL offers AISI 348 in plate and sheet form across a practical range of thicknesses and surface finishes.
AISI 348 is frequently compared with a240 347, a240 321, a240 304, a240 304l, a240 316ti and a240 310s when selecting stabilized grades for high-temperature or specialized service. SHH STEEL provides technical support to help customers choose the most appropriate material.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 348 / UNS S34800 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, related nuclear / high-temp specs | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Solution Annealed | Standard |
| Thickness Range | 0.5 mm – 80 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 2000–3000 mm | Available |
| Length | Up to 12000 mm or cut-to-length | Available |
| Surface Finish | 2B, No.1, BA, No.4 | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
SHH STEEL can supply AISI 348 dual-certified to ASTM A240 / ASME SA240 when required by the project.
Chemical Composition
Typical Chemical Composition of AISI 348 (UNS S34800):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 17.00 – 19.00 |
| Nickel (Ni) | 9.00 – 13.00 |
| Niobium (Nb/Cb) | 10 × C min – 1.00 max |
| Cobalt (Co) | ≤ 0.20 (typical controlled limit) |
| Tantalum (Ta) | Restricted |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
The combination of niobium stabilization and controlled low cobalt (and tantalum) content is the defining feature of AISI 348. Niobium provides excellent resistance to intergranular corrosion, while the restricted cobalt content makes the grade suitable for nuclear applications where reduced induced radioactivity is important. SHH STEEL carefully controls composition to meet both stabilization and low-cobalt requirements.
Mechanical Properties
Annealed Condition (typical values)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 515 MPa (75 ksi) |
| Yield Strength (0.2%) | ≥ 205 MPa (30 ksi) |
| Elongation (in 50 mm) | ≥ 40% |
| Hardness | ≤ 217 HB |
AISI 348 offers mechanical properties similar to AISI 347 and 321, with good strength, excellent ductility and toughness. The compositional controls do not significantly affect room-temperature mechanical properties. SHH STEEL supplies material with consistent mechanical properties suitable for fabrication and welding.
Physical Properties Density is approximately 7.90–8.00 g/cm³. The grade is non-magnetic in the annealed condition. Melting range is approximately 1400–1425°C.
Material Comparison
| Grade | Stabilization | Special Control | Intergranular Corrosion Resistance | High-Temp Suitability | Typical Preference |
|---|---|---|---|---|---|
| AISI 304 | None | — | Moderate | Moderate | General purpose |
| AISI 304L | Low carbon | — | Excellent | Moderate | Heavy welded constructions |
| AISI 321 | Titanium | — | Excellent | Better | Ti-stabilized high-temp service |
| AISI 347 | Niobium | — | Excellent | Better | Nb-stabilized high-temp service |
| AISI 348 | Niobium | Low Co / Ta | Excellent | Better | Nuclear + Nb-stabilized high-temp |
| AISI 316Ti | Titanium | Mo addition | Excellent | Better | Stabilized high-temp chloride service |
AISI 348 is essentially a controlled low-cobalt version of a240 347. It is selected when both niobium stabilization and minimized cobalt content are required, particularly for nuclear applications. For general high-temperature stabilized service without cobalt restrictions, SHH STEEL recommends a240 347 or a240 321.
Corrosion Resistance
AISI 348 offers good resistance to atmospheric corrosion, fresh water and many mild to moderate chemical environments, similar to standard 347 and 321. The niobium stabilization provides excellent resistance to intergranular corrosion after welding or exposure to the sensitization temperature range.
In chloride-containing environments, AISI 348 can be susceptible to pitting and stress corrosion cracking. For improved pitting resistance, SHH STEEL recommends a240 316l or a240 316ti. For severe high-temperature oxidizing service, a240 310s is preferred.
Weldability
AISI 348 has excellent weldability due to niobium stabilization. Matching or 347/348-type filler metals are commonly used. The stabilization effectively prevents intergranular corrosion in the heat-affected zone, making post-weld annealing generally unnecessary for most applications.
SHH STEEL recommends proper welding procedures and post-weld cleaning to achieve optimum corrosion performance, especially for nuclear or critical high-temperature service.
Heat Treatment
AISI 348 is normally supplied in the solution-annealed condition by SHH STEEL.
Recommended solution annealing temperature range is 980–1150°C, followed by rapid cooling. Proper annealing ensures that niobium is available for effective stabilization and optimizes both room-temperature ductility and high-temperature performance. SHH STEEL controls heat treatment to ensure consistent quality.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 348 2B – most common for general fabrication |
| No.1 | Hot-rolled, annealed and pickled | AISI 348 No.1 – industrial plate |
| BA | Bright Annealed | AISI 348 BA – cleaner surface applications |
| No.4 | Brushed finish | AISI 348 No.4 – architectural / specialized surfaces |
SHH STEEL regularly supplies AISI 348 in 2B and No.1 finishes, and can provide other finishes according to project requirements.
Tolerances
Dimensional tolerances for AISI 348 Stainless Steel Plate supplied by SHH STEEL generally conform to ASTM A480 practices.
Typical available size range is thickness 0.5 mm – 80 mm, width up to 2000–3000 mm, and length up to 12000 mm or cut-to-length. SHH STEEL provides precise dimensional control and can support tighter tolerances when required.
Equivalent Material Grades
| Grade / Designation | Standard / Region | Notes |
|---|---|---|
| AISI 348 | — | — |
| UNS S34800 | Unified Numbering System | — |
| ASTM A240 Type 348 | ASTM A240 | When dual certified |
| Related Nb-stabilized + low Co | EN / JIS / GB | Approximate national equivalents |
| Related 347 / 321 | Multiple | Standard Nb / Ti-stabilized variants |
Related grades for comparison include a240 347, a240 321, a240 304, a240 304l, a240 316ti and a240 310s.
Applications
AISI 348 is selected for welded constructions requiring niobium stabilization and controlled low cobalt content, particularly in nuclear and specialized high-temperature service. Typical applications of AISI 348 include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Nuclear Industry | AISI 348 components requiring low cobalt for reduced radioactivity |
| Heat Exchangers & Boilers | AISI 348 heat exchanger components and high-temperature parts |
| Chemical & Process Industry | AISI 348 tanks, vessels, piping and process equipment |
| Furnace & Heat Treatment | AISI 348 furnace components, fixtures and supports |
| Power Generation | AISI 348 high-temperature ducting and structural parts |
| Expansion Joints | AISI 348 expansion joints and flexible components |
| General High-Temperature Service | AISI 348 welded structures operating at elevated temperature |
SHH STEEL supplies AISI 348 for these specialized and high-temperature applications with consistent quality. For related industry solutions, see our energy industry, petrochemical industry and equipment manufacturing pages. Supporting services include steel cutting services and steel welding services.
Why Choose SHH STEEL
SHH STEEL is a China steel mill-Direct Supply specializing in stainless steel plate and sheet. By working directly with major Chinese stainless steel mills, SHH STEEL supplies AISI 348 with the following advantages:
- Genuine China steel mill-Direct Supply pricing
- Consistent quality and complete heat traceability
- Full Mill Test Certificates (EN 10204 3.1)
- Niobium-stabilized low-cobalt material optimized for nuclear and high-temperature service
- Flexible dimensions and surface finishes (including AISI 348 2B and AISI 348 No.1)
- Technical support for selection among 347, 348, 321 and related stabilized grades
- Value-added services including steel cutting services, steel welding services and worldwide shipping service
For more information about our company and full product range, please visit China steel Mill Agent-SHH STEEL.
FAQ
- What is the main difference between AISI 348 and AISI 347?AISI 348 has controlled low cobalt and tantalum content in addition to niobium stabilization. This makes it suitable for nuclear applications where minimized induced radioactivity is required. SHH STEEL recommends 348 when low-cobalt requirements apply.
- Is AISI 348 suitable for general high-temperature service?Yes. It offers the same excellent resistance to intergranular corrosion as 347 and can be used in similar high-temperature welded applications. SHH STEEL can supply both grades depending on project specifications. Q: How does AISI 348 compare
- How does AISI 348 compare with AISI 321?Both are stabilized grades. 348 uses niobium with low-cobalt control, while 321 uses titanium. Performance in intergranular corrosion resistance is similar. SHH STEEL can help select the appropriate grade based on specific requirements.
- Is AISI 348 magnetic?Non-magnetic in the annealed condition. It may become slightly magnetic after heavy cold working. SHH STEEL supplies fully annealed material as standard.
- What is the density of AISI 348?Approximately 7.90–8.00 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Can AISI 348 be used in chloride environments?It has limited resistance to pitting in chlorides. For better performance, SHH STEEL recommends molybdenum-bearing grades such as 316L or 316Ti.
- Does SHH STEEL supply dual-certified ASTM A240 / AISI 348 material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 348 Stainless Steel Plate is a niobium-stabilized austenitic grade with controlled low cobalt and tantalum content. It offers excellent resistance to intergranular corrosion after welding while meeting specialized compositional requirements for nuclear applications. It is also suitable for general high-temperature welded service similar to AISI 347.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 348 Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 348 2B and AISI 348 No.1), or a competitive quotation.
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