Alloy 825 Tubing
Alloy 825 Tubing
Alloy 825 is an austenitic nickel-iron-chromium alloy also defined by additions of molybdenum, copper and titanium. It was developed to provide exceptional resistance to numerous corrosive environments, both oxidizing and reducing. With a nickel content range between 38%–46%, this grade exhibits pronounced resistance to stress corrosion cracking (SCC) induced by chlorides and alkalis. The chromium and molybdenum content also provides good pitting resistance in all environments except strongly oxidizing chloride solutions. Utilized as an effective material in a wide variety of process environments, alloy 825 maintains good mechanical properties from cryogenic temperatures up to 1,000° F.
Product Specifications
ASTM B163, B829 / ASME SB163 / NACE MR0175
Size Range
Outside Diameter (OD) | Wall Thickness |
.250”–.750” | .035”–.065” |
Cold finished and bright annealed tube.
Chemical Requirements
Alloy 825 (UNS N08825)
Composition %
Ni | Cu | Mo | Fe | Mn | C Carbon | Si | S | Cr Chromium | Al | Ti |
38.0–46.0 | 1.5–3.0 | 2.5–3.5 | 22.0 min | 1.0 max | 0.05 max | 0.5 max | 0.03 max | 19.5–23.5 | 0.2 max | 0.6–1.2 |
Chemical Requirements
Alloy 825 (UNS N08825)
Composition %
Ni | Cu | Mo | Fe | Mn | C | Si | S | Cr | Al | Ti |
38.0–46.0 | 1.5–3.0 | 2.5–3.5 | 22.0 min | 1.0 max | 0.05 max | 0.5 max | 0.03 max | 19.5–23.5 | 0.2 max | 0.6–1.2 |
Dimensional Tolerances
OD | OD Tolerance | Wall Tolerance |
.250"–.500" excl | +.004”/-.000” | ± 10% |
.500”–.750” incl | +.005”/-.000” | ± 10% |
Mechanical Properties
Yield Strength: | 35 ksi min |
Tensile Strength: | 85 ksi min |
Elongation (min 2"): | 30% |
Hardness (Rockwell B Scale) | 90 HRB max |
Fabrication
This material has excellent formability, typical of nickel-base alloys, allowing the material to be bent to extremely small radii. Annealing after bending is not normally necessary. Upon request, PAC Stainless will provide additional information regarding the heating, hot or cold forming, machining and welding of Alloy 825 product.
Industry Applications
Chemical Process
With its ability to resist chloride-ion stress-corrosion cracking as well as withstand reducing conditions in the presence of sulfuric and phosphoric acids, it can be argued that alloy 825 is the preferred alloy for chemical processing applications.
Fabrication
Alloy 825 is used for pickling operations including heating coils and tanks due to its ability to withstand acids. See fabrication for more information.
Food & Beverage
Alloy 825’s corrosive resistant properties make it an ideal candidate for use in the food industry, specifically food processing equipment.
Oil & Gas
Molybdenum, copper, and titanium make 825 an effective material in a wide variety of process environments. It is used for control lines on offshore oil platforms because of its ability to withstand the oxidizing and reducing effects of seawater and chemicals.
Power Generation
In the power generation industry, alloy 825 is used for radioactive waste handling, including fuel element dissolvers, due to its long-term thermal stability.
