Alloy 825
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Product Description:
Alloy 825 is a corrosion-resistant, nickel-iron-chromium alloy that is highly resistant to a variety of harsh environments, including acidic, alkaline, and aqueous media. It is composed primarily of nickel, chromium, iron, and molybdenum, which provide excellent resistance to corrosion, particularly in sulfuric, phosphoric, and nitric acids, as well as to pitting and crevice corrosion. Alloy 825 is highly versatile and is used in industries such as chemical processing, oil and gas, pollution control, and marine environments.
The alloy is also known for its excellent weldability, formability, and resistance to stress corrosion cracking. These characteristics make it suitable for both high- and low-temperature environments, making it ideal for a wide range of applications, particularly in aggressive environments.
Features of Alloy 825:
- Excellent Corrosion Resistance: Highly resistant to corrosion in a wide range of environments, including acids, alkalis, and saltwater.
- Resistance to Pitting and Crevice Corrosion: Alloy 825 is designed to resist localized corrosion such as pitting and crevice corrosion, which is critical in marine and chemical processing environments.
- Stress Corrosion Cracking Resistance: The alloy offers superior resistance to stress corrosion cracking, especially in chloride environments, making it ideal for applications exposed to such conditions.
- Oxidation Resistance: Alloy 825 has excellent oxidation resistance up to 870°C (1600°F), which makes it suitable for elevated temperature applications.
- Good Weldability: It can be easily welded using standard techniques, providing versatility in fabrication.
- Non-Sensitizing: This alloy does not suffer from sensitization, which reduces the risk of intergranular corrosion when exposed to heat.
- Good Mechanical Properties: Alloy 825 retains good mechanical properties at both high and low temperatures, providing reliability in extreme conditions.
Specifications:
- ASTM B425
- ASTM B424
- UNS N08825
- ASME SB-425
- DIN 2.4858
- BS 3076 NA 16
These specifications highlight Alloy 825’s broad range of industrial applications, ensuring its compatibility with various standards for pressure vessels, chemical equipment, and other industrial machinery.
Composition of Alloy 825:
Element | Percentage |
---|---|
Nickel (Ni) | 38.0-46.0% |
Chromium (Cr) | 19.5-23.5% |
Iron (Fe) | Balance |
Molybdenum (Mo) | 2.5-3.5% |
Copper (Cu) | 1.0-3.0% |
Titanium (Ti) | 0.6-1.2% |
Aluminum (Al) | 0.2% Max |
Carbon (C) | 0.05% Max |
Manganese (Mn) | 1.0% Max |
Silicon (Si) | 0.5% Max |
Sulfur (S) | 0.03% Max |
Phosphorus (P) | 0.04% Max |
Physical Properties:
Property | Value |
---|---|
Density | 8.0 g/cm³ |
Melting Point | 1300-1350°C (2372-2462°F) |
Hardness (BHN) | 200-250 BHN |
Tensile Strength | 550 MPa (80,000 psi) |
Yield Strength | 240 MPa (35,000 psi) |
Elongation | 30% |
Modulus of Elasticity | 200 GPa |
Thermal Conductivity | 14.9 W/m·K |
Coefficient of Thermal Expansion | 16.5 x 10^-6 /°C |