ASTM B424 UNS N08825 Plate & Sheet | Alloy 825 2.4858
ASTM B424 UNS N08825 plate and sheet are nickel-iron-chromium-molybdenum-copper alloy products designed for corrosive chemical, acid-processing, oil and gas, marine and pollution-control applications. Alloy 825 combines high nickel and chromium contents with molybdenum, copper and titanium to provide resistance to chloride stress-corrosion cracking, reducing acids, oxidizing environments, pitting and crevice corrosion.
We supply ASTM B424 / ASME SB-424 UNS N08825 plate, sheet and strip in annealed condition, with cut-to-size options, PMI, dimensional inspection and EN 10204 3.1 certification.
ASTM B424 N08825 Plate & Sheet Specification
| Item | Specification |
|---|---|
| Material Standard | ASTM B424 / ASME SB-424 |
| UNS | N08825 |
| Material | Alloy 825 |
| EN / W.Nr. | 2.4858 |
| Material Family | Nickel-Iron-Chromium-Molybdenum-Copper Alloy |
| Product Forms | Plate / Sheet / Strip |
| Condition | Annealed |
| Typical Supply | Hot Rolled / Cold Rolled |
| Surface | Annealed / Pickled as applicable |
| Certification | EN 10204 3.1 / 3.2 when specified |
What Is ASTM B424 UNS N08825?
ASTM B424 covers plate, sheet and strip manufactured from nickel-iron-chromium-molybdenum-copper alloys including UNS N08825.
UNS N08825 is a corrosion-resistant nickel alloy containing significant amounts of:
- Nickel
- Chromium
- Iron
- Molybdenum
- Copper
- Titanium
This combination provides resistance to both oxidizing and reducing environments and makes N08825 particularly useful in chemical-processing and acid-service equipment.
The principal material designations are:
| System | Designation |
|---|---|
| ASTM | B424 UNS N08825 |
| ASME | SB-424 UNS N08825 |
| UNS | N08825 |
| EN / W.Nr. | 2.4858 |
| Material | Alloy 825 |
ASTM B424 Plate vs Sheet vs Strip
ASTM B424 includes several rolled-product forms.
| Product Form | General Description |
|---|---|
| Plate | Thicker flat-rolled product used for vessels, equipment and fabricated components |
| Sheet | Thinner flat-rolled product supplied in standard widths and lengths |
| Strip | Narrow flat-rolled product, generally supplied in coil or cut lengths |
Plate and sheet may be produced by hot rolling or cold rolling depending on thickness and required dimensional tolerance.
Typical commercial supply ranges should be confirmed according to thickness, width, length, quantity and manufacturing route.
ASTM B424 N08825 Chemical Composition
| Element | UNS N08825 |
|---|---|
| Nickel, Ni | 38.0–46.0% |
| Chromium, Cr | 19.5–23.5% |
| Iron, Fe | 22.0% min |
| Molybdenum, Mo | 2.5–3.5% |
| Copper, Cu | 1.5–3.0% |
| Titanium, Ti | 0.6–1.2% |
| Carbon, C | 0.05% max |
| Manganese, Mn | 1.0% max |
| Silicon, Si | 0.5% max |
| Sulfur, S | 0.03% max |
| Aluminum, Al | 0.2% max |
The high Ni-Cr-Mo-Cu content is the main reason for the alloy’s broad corrosion resistance.
Actual heat chemistry is reported on the Material Test Certificate.
ASTM B424 N08825 Mechanical Properties
Typical ASTM B424 minimum room-temperature mechanical requirements for annealed UNS N08825 plate, sheet and strip include:
| Property | Minimum Requirement |
|---|---|
| Tensile Strength | 586 MPa / 85 ksi |
| Yield Strength | 241 MPa / 35 ksi |
| Elongation | 30% |
Actual mechanical test results are reported on the supplied MTC.
Mechanical acceptance criteria shall follow the ordered ASTM B424 edition and applicable product condition.
Heat Treatment of ASTM B424 N08825
ASTM B424 N08825 plate, sheet and strip are supplied in the required annealed condition.
Proper annealing is important for maintaining:
- Corrosion resistance
- Ductility
- Mechanical properties
- Stable austenitic structure
- Fabrication performance
Alloy 825 contains titanium, which contributes to stabilization against sensitization under suitable processing and heat-treatment conditions.
Typical surface conditions can include:
Hot Rolled + Annealed + Pickled
or
Cold Rolled + Annealed
depending on thickness and product form.
Corrosion Resistance of UNS N08825 Plate
One of the main advantages of N08825 plate and sheet is resistance to a broad range of corrosive environments.
Sulfuric Acid Resistance
The combination of nickel, molybdenum and copper provides useful resistance in many sulfuric acid environments.
Actual performance depends on:
- Acid concentration
- Temperature
- Contaminants
- Flow conditions
- Oxidizing potential
Phosphoric Acid Resistance
UNS N08825 is widely selected for equipment exposed to phosphoric acid and related chemical-processing environments.
Chloride Stress-Corrosion Cracking
The relatively high nickel content provides strong resistance to chloride-ion-induced stress-corrosion cracking compared with many conventional stainless steels.
Pitting and Crevice Corrosion
Molybdenum contributes to resistance against:
- Pitting corrosion
- Crevice corrosion
- Localized attack in chloride-bearing media
The final material selection should always be based on actual operating conditions.
Typical Plate & Sheet Supply
UNS N08825 can be supplied as:
- Hot-Rolled Plate
- Cold-Rolled Plate
- Hot-Rolled Sheet
- Cold-Rolled Sheet
- Strip
- Cut plate
- Custom-size sheet
Typical supply options can include:
- Standard mill sizes
- Fixed-width plate
- Fixed-length plate
- Cut-to-size pieces
- Custom blanks
- Drawing-specific dimensions
Thickness, width and length availability depend on mill production range and required quantity.
Processing & Fabrication
ASTM B424 N08825 plate and sheet can be supplied as full-size material or processed to project dimensions.
Available fabrication options can include:
- Cutting
- Shearing
- Bending
- Rolling
- Forming
- Machining
- Welding preparation
- Custom blanks
Because N08825 is a high-nickel corrosion-resistant alloy, fabrication procedures should account for its work-hardening characteristics and thermal properties.
Welding procedures, filler metal and heat input should be selected according to the application and fabrication specification.
Alloy 825 vs Alloy 625 Plate
Alloy 825 and Alloy 625 are both corrosion-resistant nickel alloys but have different alloy systems and application strengths.
| Item | Alloy 825 / N08825 | Alloy 625 / N06625 |
|---|---|---|
| Base System | Ni-Fe-Cr-Mo-Cu | Ni-Cr-Mo-Nb |
| Ni | 38–46% | 58% min |
| Cr | 19.5–23.5% | 20–23% |
| Mo | 2.5–3.5% | 8–10% |
| Cu | 1.5–3.0% | Low |
| Nb + Ta | No major addition | 3.15–4.15% |
| Main Strength | Acid and chemical corrosion resistance | Higher strength and aggressive chloride resistance |
| Typical Use | Chemical processing / acid systems | Offshore / severe corrosive service |
Neither alloy is universally superior.
The appropriate material depends on process chemistry, temperature, strength requirements and corrosion environment.
Applications
ASTM B424 N08825 plate and sheet are commonly used in:
- Chemical-processing equipment
- Sulfuric acid systems
- Phosphoric acid systems
- Acid-production equipment
- Pickling equipment
- Pollution-control systems
- Oil and gas processing
- Marine equipment
- Heat exchangers
- Pressure vessels
- Process vessels
- Storage tanks
- Fabricated corrosion-resistant equipment
The alloy is particularly useful where resistance to both reducing and oxidizing environments is required.
Related UNS N08825 Products
A complete N08825 piping or equipment system can include:
| Component | Typical Specification |
|---|---|
| Plate / Sheet | ASTM B424 UNS N08825 |
| Pipe | ASTM B423 UNS N08825 |
| Butt-Weld Fitting | ASTM B366 UNS N08825 |
| Forged Flange | ASTM B564 UNS N08825 |
ASTM B424 N08825 plate and sheet can be supplied together with matching N08825 pipe, fittings and forged flanges according to project requirements.
Inspection & Certification
ASTM B424 N08825 plate and sheet can be supplied with:
- EN 10204 Type 3.1 MTC
- EN 10204 Type 3.2 when specified
- Heat chemical analysis
- Tensile test results
- Yield-strength results
- Elongation results
- Dimensional inspection
- Thickness inspection
- Visual examination
- PMI
- Surface inspection
- UT for plate when specified
- Third-party inspection
- Full heat-number traceability
Additional inspection requirements can be incorporated according to the project ITP or purchase specification.
Frequently Asked Questions
What is ASTM B424 UNS N08825?
ASTM B424 UNS N08825 is a nickel-iron-chromium-molybdenum-copper alloy specification for corrosion-resistant plate, sheet and strip. The material is commonly used in chemical, acid-processing and chloride-containing environments.
What is the difference between N08825 plate and sheet?
Both plate and sheet are flat-rolled N08825 products, but plate generally refers to thicker material while sheet is supplied in thinner gauges according to the applicable dimensional requirements of ASTM B424.
What are the minimum mechanical properties of ASTM B424 N08825?
For annealed N08825 material, typical ASTM B424 minimum requirements include approximately 586 MPa tensile strength, 241 MPa yield strength and 30% elongation.
Is UNS N08825 suitable for sulfuric acid service?
UNS N08825 is widely used in many sulfuric acid environments because of its nickel, molybdenum and copper content.
Actual suitability depends on acid concentration, temperature, contaminants and process conditions.
What pipe, fittings and flanges match N08825 plate?
A typical matching material system includes:
ASTM B423 N08825 Pipe + ASTM B366 N08825 Fittings + ASTM B564 N08825 Flanges + ASTM B424 N08825 Plate
according to project requirements.
ASTM B424 UNS N08825 Plate Sheet
ASTM B424 N08825 Plate & Sheet Supplier
We supply ASTM B424 / ASME SB-424 UNS N08825 plate, sheet and strip for chemical, acid-processing, oil and gas, marine and corrosion-resistant equipment applications.
Available supply options include:
Hot-Rolled Plate / Cold-Rolled Sheet / Cut-to-Size Plate / Custom Blanks / Annealed Material / PMI / UT / EN 10204 Certification
For quotation, please specify:
Material + Product Form + Thickness + Width + Length + Quantity + Condition + Standard + Inspection Requirements
Example 1:
ASTM B424 UNS N08825 Plate, 12 mm × 2000 mm × 6000 mm, Annealed & Pickled, EN 10204 3.1
Example 2:
ASTM B424 UNS N08825 Sheet, 2 mm × 1500 mm × 3000 mm, Annealed, EN 10204 3.1
