INCOLOY® Alloy 825 Product Introduction
Introduction
INCOLOY® alloy 825 is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. It is renowned for its exceptional corrosion resistance in both reducing and oxidizing environments, making it suitable for various demanding applications across industries. This article provides a comprehensive introduction to INCOLOY® alloy 825, covering its chemical composition, mechanical properties, performance at different temperatures, industry applications, shapes, sizes, production standards, welding, machining, polishing, heat treatment, cold working, advantages, disadvantages, and similar products.
Chemical Composition
The chemical composition of INCOLOY® alloy 825 is detailed below:
| Element | Composition (%) |
|---|---|
| Nickel (Ni) | 38.0 – 46.0 |
| Iron (Fe) | 22.0 min |
| Chromium (Cr) | 19.5 – 23.5 |
| Molybdenum (Mo) | 2.5 – 3.5 |
| Copper (Cu) | 1.5 – 3.0 |
| Titanium (Ti) | 0.6 – 1.2 |
| Aluminum (Al) | 0.2 max |
| Carbon (C) | 0.05 max |
| Manganese (Mn) | 1.0 max |
| Sulfur (S) | 0.03 max |
| Silicon (Si) | 0.5 max |
| Phosphorus (P) | 0.03 max |
Mechanical Properties
Mechanical properties of INCOLOY® alloy 825 are essential for understanding its performance under various conditions:
| Property | Value |
|---|---|
| Tensile Strength (Room Temp.) | 550 MPa (minimum) |
| Yield Strength (0.2% offset) | 220 MPa (minimum) |
| Elongation (in 50 mm) | 30% (minimum) |
| Hardness (HV) | 138 (typical) |
Performance at Different Temperatures
The performance of INCOLOY® alloy 825 at elevated temperatures is crucial for its application suitability:
| Temperature Range | Performance |
|---|---|
| Ambient to 315°C | Excellent resistance to aqueous corrosion |
| 315°C to 870°C | Good mechanical properties and oxidation resistance |
| Above 870°C | Susceptible to embrittlement and reduced corrosion resistance |
Industry Applications
INCOLOY® alloy 825 finds extensive use in various industries due to its corrosion resistance and mechanical properties:
- Chemical Processing: Components in sulfuric acid environments.
- Oil and Gas: Equipment exposed to sour gas and seawater.
- Nuclear: Control rod component.
- Marine: Seawater cooling systems.
- Food Processing: Equipment handling acidic foods.
Shapes, Sizes, and Production Standards
INCOLOY® alloy 825 is available in various forms to meet diverse application requirements:
- Forms: Sheets, plates, bars, pipes, tubes, fittings, and forgings.
- Sizes: Customizable based on application specifications.
- Production Standards: ASTM B425, ASTM B423, ASTM B163, ASTM B704, ASTM B705, ASME SB425, ASME SB163, ASME SB423, DIN 2.4858, BS 3076NA16, and others.
Standards and Corresponding Grades
Standards and corresponding grades vary by country and application, ensuring compliance and interoperability:
| Country | Standards | Corresponding Grades |
|---|---|---|
| United States | ASTM, ASME | UNS N08825, Alloy 825 |
| Germany | DIN | 2.4858 |
| France | AFNOR | NC21FeD |
| United Kingdom | BS | NA16 |
| Japan | JIS | NCF 825 |
| China | GB | GHM32 |
Welding, Machining, Polishing, Heat Treatment, Cold Working
INCOLOY® alloy 825 exhibits good weldability and machinability under controlled conditions. It can be welded using conventional techniques, although precautions are necessary to avoid cracking. Machining of the alloy is performed using carbide tools due to its work-hardening tendency. Polishing improves surface finish and corrosion resistance. Heat treatment involves annealing at specific temperatures to achieve desired mechanical properties. Cold working enhances strength but requires careful monitoring to avoid cracking.
Advantages and Disadvantages
| Advantages | Disadvantages |
|---|---|
| Excellent corrosion resistance in various media | Expensive raw material cost |
| High strength and toughness | Limited availability in some forms and sizes |
| Good weldability and machinability | Prone to stress corrosion cracking in certain environments |
Similar Products
Similar products to INCOLOY® alloy 825 include other nickel-based alloys such as INCONEL® alloy 625 and HASTELLOY® C-276, which offer comparable corrosion resistance and mechanical properties in specific applications.
Conclusion
INCOLOY® alloy 825 is a versatile nickel-iron-chromium alloy renowned for its exceptional corrosion resistance, mechanical properties, and suitability across diverse industries. Its chemical composition, mechanical properties, performance at different temperatures, and various applications make it a preferred choice for critical environments requiring reliability and longevity.
This comprehensive introduction provides insight into the capabilities and applications of INCOLOY® alloy 825, facilitating informed decisions for industrial and engineering applications.