ASTM B423 Seamless UNS N08825 Alloy Pipe and Tube
- Grade: UNS N08825, UNS N08221
- Outside Diameter (OD): NPS 1/8″ -30″, Wall Thickness (WT): SCH 5S, 10S, 40S, 80S
- Outside Diameter (OD): 6.35-152.4mm, Wall Thickness (WT): 1.65-8.56mm
Features
ASTM B423 Nickel Alloy (UNS N08825 and N08221) Seamless Pipe and Tube
Chemical Composition (wt.%)
| Element | UNS N08825 | UNS N08221 |
|---|---|---|
| Nickel | 38.0–46.0% | 39.0–46.0% |
| Chromium | 19.5–23.5% | 20.0–22.0% |
| Iron | 22.0% min | 22.0% min |
| Manganese | 1.0% max | 1.0% max |
| Carbon | 0.05% max | 0.025% max |
| Copper | 1.5–3.0% | 1.5–3.0% |
| Silicon | 0.5% max | 0.5% max |
| Sulfur | 0.03% max | 0.03% max |
| Aluminum | 0.2% max | 0.2% max |
| Titanium | 0.6–1.2% | 0.6–1.0% |
| Molybdenum | 2.5–3.5% | 5.0–6.5% |
Mechanical Properties of Pipe and Tube
| Condition and Size | Tensile Strength (min) | Yield Strength (0.2% Offset, min) | Elongation in 2 in. or 50 mm (min) |
| UNS N08825 hot-finished annealed | 75 ksi (517 MPa) | 25 ksi (172 MPa) | 30% |
| UNS N08825 cold-worked annealed | 85 ksi (586 MPa) | 35 ksi (241 MPa) | 30% |
| UNS N08825 hot-forming quality* | – | – | – |
| UNS N08221 cold-finished annealed | 79 ksi (545 MPa) | 34 ksi (234 MPa) | 30% |
* Hot-forming quality is furnished to chemical requirements and surface inspection only. No mechanical properties are required.
Technical Specifications
| Specification | Value |
| Standard | ASTM B423 Nickel-Iron-Chromium-Molybdenum-Copper Alloy Seamless Pipe and Tube |
| Grade | UNS N08825 (EN 2.4858, Alloy 825, NiCr21Mo), UNS N08221 |
| Manufacturing Process | cold-worked and hot-finished |
| Seam Type | Seamless |
| Pipe Size | Outside Diameter (OD) Range: NPS 1/8″ -6″, Wall Thickness (WT) Range: 1.47 – 13.2mm |
| Length | 6000-12000mm |
| Delivery Condition | Annealed |
| Inspection Certificate | EN 10204 Type 3.1 (Mill Test Certificate), EN 10204 Type 3.2 (Witness Testing or 3rd Party Inspection) |
| Test | Chemical analysis, Tensile test, Flattening test, Expansion test, Hydrostatic test, Nondestructive testing (NDT), Intergranular corrosion test, Metallographic examination |
Key Properties
Excellent resistance to sulfuric acid: Performs well in a wide range of sulfuric acid concentrations and temperatures.
Resistance to other acids: Offers good resistance to phosphoric acid, nitric acid, organic acids, and some hydrochloric acid solutions.
Resistance to localized corrosion: Resists pitting, crevice corrosion, and stress corrosion cracking in chloride solutions.
Good high-temperature strength: Maintains mechanical properties at elevated temperatures.
Packing
Pipes with plain or bevelled ends, equipped with caps or bevel protectors. Small diameter pipes are packed in wooden crates or wrapped in woven bags and hexagonally bundled. Large-diameter pipes are loosely packed and wrapped in woven bags.
Application
Heat exchangers: Used in processes involving sulfuric acid, phosphoric acid, and other corrosive chemicals.
Process piping: Suitable for transporting corrosive fluids and gases in chemical plants and refineries.
Reactors and vessels: Components in chemical processing equipment exposed to aggressive environments.
Downhole tubing and equipment: Resists sour gas environments containing hydrogen sulfide (H2S) and carbon dioxide (CO2).
Offshore platforms and pipelines: Offers good resistance to seawater corrosion, making it suitable for marine applications.
Refinery equipment: Used for handling sour crude oil and natural gas processing.
Flue gas desulfurization (FGD) systems: Components in scrubbers and piping systems for handling sulfuric acid and other corrosive byproducts.
Wastewater treatment: Used for handling acidic wastewater and chemical treatment processes.
Pulp and paper industry: Equipment exposed to bleaching chemicals and other corrosive media.
Pickling and metal finishing: Handling sulfuric acid and other corrosive solutions.
Nuclear fuel reprocessing: Components exposed to corrosive solutions in nuclear fuel reprocessing plants.
