Incoloy Tubes ASME SB163- UNS N08825
ASME SB163 UNS N08825 Incoloy Tubes
Incoloy Tubes manufactured to ASME SB163 UNS N08825 standards are high-performance nickel-iron-chromium alloy tubes designed for extreme environments. Known for exceptional corrosion resistance, high-temperature strength, and durability, these tubes are widely used in chemical processing, oil & gas, power plants, and marine engineering.
- Chemical composition & mechanical properties
- Key advantages over similar alloys
- Industry applications & common sizes
- U-bend tube specifications
- FAQs for engineers & buyers
1. What Are ASME SB163 UNS N08825 Incoloy Tubes?
ASME SB163 UNS N08825 (commonly called Incoloy 825) is a nickel-iron-chromium alloy enhanced with molybdenum (Mo) and copper (Cu) for superior resistance to:
- Sulfuric & phosphoric acid corrosion
- Oxidation at high temperatures (up to 540°C / 1000°F)
- Stress corrosion cracking (SCC) in chloride environments
These tubes comply with ASME Boiler and Pressure Vessel Code, ensuring reliability in critical industrial applications.
2. ASME SB163 UNS N08825 Chemical Composition
The alloys corrosion resistance comes from its balanced composition:
| Element | Percentage (%) | Role in Alloy Performance |
|---|---|---|
| Nickel (Ni) | 38.0 - 46.0 | Enhances corrosion resistance & high-temperature strength |
| Chromium (Cr) | 19.5 - 23.5 | Provides oxidation resistance |
| Iron (Fe) | 22.0 - 33.0 | Base metal for structural integrity |
| Molybdenum (Mo) | 2.5 - 3.5 | Improves pitting/crevice corrosion resistance |
| Copper (Cu) | 1.5 - 3.0 | Boosts resistance to sulfuric acid |
| Manganese (Mn) | ≤ 1.0 | Deoxidizer for improved weldability |
| Carbon (C) | ≤ 0.05 | Minimizes carbide precipitation |
3. Mechanical Properties of ASME SB163 UNS N08825 Tubes
| Property | Value | Significance |
|---|---|---|
| Tensile Strength | ≥ 550 MPa | Withstands high-pressure environments |
| Yield Strength | ≥ 240 MPa | Resists deformation under load |
| Elongation | ≥ 30% | High ductility for forming & welding |
| Hardness | ≤ 85 HRB | Ensures machinability without brittleness |
Comparison with Similar Alloys:
- Better chloride resistance than Inconel 600
- Higher strength than Hastelloy C276 in acidic environments
4. Applications of ASME SB163 UNS N08825 Tubes
These tubes are ideal for:
- Chemical Processing – Reactors, acid storage, pickling tanks
- Oil & Gas – Downhole tubing, heat exchangers, sour gas handling
- Power Generation – Boiler tubes, flue gas desulfurization
- Marine Engineering – Seawater piping, offshore platforms
- Pollution Control – Scrubbers, exhaust systems
5. Available Sizes & Specifications
| Parameter | Range |
|---|---|
| Outer Diameter (OD) | 6 mm – 219 mm |
| Wall Thickness (WT) | 0.5 mm – 20 mm |
| Length | Up to 12 meters |
| Standards | ASME SB163, ASTM B163, DIN 17751 |
6. U-Bend ASME SB163 UNS N08825 Tubes
U-bend tubes are critical in heat exchangers & condensers due to:
- Superior stress corrosion cracking resistance
- High thermal stability in cyclic heating/cooling
- Compliance with ASME standards for pressure applications
7. FAQs for Engineers & Buyers
Q1: Can ASME SB163 N08825 tubes handle sulfuric acid?
Yes! The copper content (1.5-3.0%) provides excellent resistance to sulfuric and phosphoric acids.
Q2: How does Incoloy 825 compare to Inconel 625?
- Incoloy 825 (N08825) is better for sulfuric acid & chloride environments.
- Inconel 625 excels in higher temperatures (up to 980°C) and oxidizing acids.
Q3: Are welded tubes available in N08825?
Yes, but seamless tubes are preferred for high-pressure applications.
Q4: What welding methods work best?
- TIG welding (GTAW) with ERNiCrMo-3 filler is recommended.
- Post-weld annealing may be required to restore corrosion resistance.
ASME SB163 UNS N08825 Incoloy Tubes offer unmatched corrosion resistance, durability, and versatility for harsh industrial environments. By understanding their composition, mechanical properties, and applications, engineers can select the right tubing for critical projects.
