Alloy 825 vs Inconel 825: Are They the Same? UNS N08825, ASTM Standards and Applications Explained
Alloy 825 vs Inconel 825 Comparison is a popular discussion among engineers and buyers interested in corrosion-resistant nickel-based alloys for various harsh industrial applications. Even though the materials mentioned above may seem the same, knowledge of the alloy composition, UNS N08825 code, ASTM standards, mechanical characteristics, and uses is critical in order to make a proper choice. The alloy in question has high corrosion resistance against acids, salt water, and hot environments and is suitable for application in different industries like chemical processing, oil and gas, marine, and power generating industries. In this article, you will find the information about Alloy 825 vs Inconel 825 comparison, ASTM standards, and characteristics.
What is Alloy 825?
Alloy 825 is a nickel iron chromium alloy which contains molybdenum, copper, and titanium. The purpose of its creation was to withstand corrosion in a highly corrosive atmosphere which includes both oxidizing and reducing mediums. It has been successfully used in the chemical processing industry, the marine industry, the oil and gas industry, and the power generation industry.
What is Inconel 825?
Inconel 825 is one of the many commercial names of this alloy that are being used commercially. This alloy is known for its very good corrosion resistance properties as well as high strength. Moreover, it has very good mechanical properties over wide range of temperatures. It is manufactured on large scale in form of pipes, tubes, flanges, plates, fittings, and bars.
Chemical Composition of Alloy 825 / Incoloy 825 (UNS N08825)
Element | Symbol | Composition (%) |
Nickel | Ni | 38.0 – 46.0 |
Chromium | Cr | 19.5 – 23.5 |
Iron | Fe | 22.0 min |
Molybdenum | Mo | 2.5 – 3.5 |
Titanium | Ti | 0.6 – 1.2 |
Copper | Cu | 1.5 – 3.0 |
Manganese | Mn | 1.0 max |
Carbon | C | 0.05 max |
Sulfur | S | 0.03 max |
Aluminum | Al | 0.2 max |
Silicon | Si | 0.5 max |
Alloy 825 Equivalent Grades and International Standards
Standard / Grade | Werkstoff Nr. | UNS | GOST | AFNOR | JIS | BS | EN |
Incoloy 825 | 2.4858 | N08825 | ЭП703 / ХН38ВТ | NFE30C20DUM | NCF 825 | NA 16 | NiCr21Mo |
Inconel 825 Physical & Mechanical Properties
Property | Value |
Density | 8.14 g/cm³ |
Melting Point | 1400 °C (2550 °F) |
Tensile Strength | 80,000 Psi / 550 MPa |
Yield Strength (0.2% Offset) | 32,000 Psi / 220 MPa |
Elongation | 30 % |
Hardness | 192 HB max |
Applications of Alloy 825
- Aerospace Industry
- Oil and Gas Processing Systems
- Offshore and Marine Equipment
- Heat Exchangers
- Pressure Vessels
- Power Generation Plants
- Pollution Control Equipment
- Pickling Equipment
Alloy 825 Pipe, Plate, Sheet and Round bar Uses
The alloy 825 pipes and inconel 825 are used in different industries according to their requirements. Some of the most common industries where this material is used are given below.
Product Form | Common Uses |
Alloy 825 Pipe | Process piping, offshore pipelines, chemical transfer lines, heat exchanger tubing, and oil and gas production systems. |
Alloy 825 Plate | Pressure vessels, storage tanks, chemical reactors, scrubbers, and flue gas desulfurization (FGD) units. |
Alloy 825 Sheet | Chemical processing equipment, heat exchanger components, ducting, industrial fabrication work, and pollution control equipment. |
Alloy 825 Round Bar | Fasteners, industrial shafts, valve components, pump parts, flanges, fittings, and precision machined components. |
Conclusion:
The Alloys 825, Inconel 825, and Incoloy 825 all are synonymous names of the same material of UNS N08825 alloy comprising of Nickel, Iron, and Chromium. To have the least possibility of any confusion in regard to the trade name, the UNS N08825 and ASTM standard should be followed according to which particular component you are buying. For instance, for seamless pipes/tubes, ASTM B423 will be followed. Due to the presence of molybdenum, copper, and titanium in the alloy composition, it is regarded as one of the best corrosion-resistant alloys when it comes to acid reduction, chloride resistance, and sour gases. Stellar Alloys is an esteemed manufacturer and supplier of high-grade alloy 825 products.
Frequently Asked Questions
There is no significant difference in composition or properties. However, Incoloy 825 is the correct trade name, while Inconel 825 is a commonly used market term.
Yes, Alloy 825 and Inconel 825 generally refer to the same nickel-iron-chromium alloy with the UNS N08825 designation.
Yes. The correct trade name is Incoloy 825. “Inconel 825” is widely used in the industry but is technically incorrect.
UNS N08825 is the Unified Numbering System (UNS) designation for Alloy 825, identifying its standardized chemical composition and material specification.
Common ASTM standards for Alloy 825 include ASTM B163, ASTM B423, ASTM B424, ASTM B425, ASTM B704, and ASTM B705, depending on the product form.
Alloy 825 is suitable for continuous service up to 550°C (1022°F) in oxidizing environments. For temperatures above 600°C, Inconel 625 or Inconel 718 is generally preferred because they offer better high-temperature strength.