UNS NO8825 Alloy Refinery Pipe Information
UNS N08825, also known as Incoloy 825, is a nickel-iron-chromium alloy widely used in refinery piping due to its excellent corrosion resistance in both oxidizing and reducing environments. Its unique chemical composition and stability make it ideal for handling the harsh corrosive media common in the petroleum refining industry.
What is the difference between UNS N06625 and UNS N08825?
Inconel 625 vs. Incoloy 825 (UNS N06625 vs. UNS N08825)
The primary difference between the two materials is their nickel content. Inconel 625 contains at least 58% nickel, while Incoloy 825 has a nickel content between 38% and 46%. This makes 625 more expensive.
Characteristics of ASTM B163 Alloy 825 UNS N08825 Pipe
Excellent resistance to reducing and oxidizing acids
Good mechanical properties at room temperature and elevated temperatures up to approximately 1020°F
Good resistance to stress corrosion cracking
Permits use in pressure vessels with wall temperatures up to 800°F
Good resistance to localized corrosion, such as pitting and crevice corrosion
Corrosion Resistance
825 Alloy Pipe is a general-purpose engineering nickel alloy with excellent resistance to acid and alkali corrosion in both oxidizing and reducing environments. The nickel content imparts effective resistance to stress corrosion cracking. It exhibits excellent corrosion resistance in a wide range of media, including sulfuric, phosphoric, nitric, and organic acids, as well as alkali (e.g., sodium hydroxide, potassium hydroxide) and hydrochloric acid solutions.
825 Alloy Pipe is resistant to boiling sulfuric acid at concentrations up to 40%, and to all sulfuric acid concentrations up to 60% at temperatures up to 80°C. It also exhibits corrosion resistance up to 66°C. 825 Alloy Pipe also offers excellent resistance to phosphoric acid at all concentrations. It offers excellent corrosion resistance to chloride-containing solutions, seawater pitting, and stress corrosion. It also exhibits good resistance to intergranular corrosion.
The excellent comprehensive performance of 825 alloy pipe is fully demonstrated in nuclear combustion dissolvers, which can handle a variety of corrosive media, such as sulfuric acid, nitric acid, and sodium hydroxide.
Chemical Composition of ASTM B163 Alloy 825 UNS NO8825 Tube
| C | MN | S | Si | Cr | Ni | Mo | Cu | Ti | Al | Fe | Other |
| 0.05 max | 1.0 max | 0.03 max | 0.5 max | 19.5 - 23.5 | 38.0 - 46.0 | 2.5 - 3.5 | 1.5 - 3.0 | 0.6 1.2 | 0.2 max | 22.0 min | 3.15 4.15 |
Mechanical Strength of Astm B163 Alloy 825 UNS NO8825 Piping
| Tensile Strength | MpaYield Strength MPa | Elongation, % |
| 586 min | 241 min | 30 min |
Physical properties of ASTM B163 Alloy 825 UNS NO8825 Tubing
| Properties | Metric | Imperial |
| Density | 8.14 g/cm³ | 0.294 lb/in³ |
| Melting point | 1385°C | 2525°F |
Available Shapes and Specifications
UNS N08825 pipe is available in both seamless and welded forms to meet specific project needs.
Available shapes: Tube, pipe, bar, plate, sheet, and fittings.
Standard Specifications: The alloy conforms to various ASTM, ASME, and ISO standards, including ASTM B423 for seamless pipe and ASTM B705/ASME SB 705 for welded pipe.
Sizes: Available in a variety of sizes and wall thicknesses, with seamless and welded options to meet varying diameter requirements.
Gnee Steel specializes in the production and sale of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. Gnee Steel's products are widely used in aerospace, chemical, electric power, automotive, and nuclear energy applications. We also offer customized alloy solutions tailored to customer needs. For alloy pricing inquiries or customized alloy solutions, please contact us for a quote at ss@gneesteel.com.
