Inconel vs Incoloy Fasteners: A Comprehensive Comparison

Incoloy fasteners, on the other hand, are made from alloys primarily composed of nickel, iron, and chromium. These fasteners are used in environments that require resistance to both high temperatures and aggressive chemical environments, such as in chemical processing and nuclear power plants.

Composition and Key Differences

1. Inconel Fasteners
   • Composition: Primarily composed of nickel (up to 72%) and chromium (up to 22%), along with iron, molybdenum, and other trace elements.
   • Temperature Resistance: Inconel fasteners can withstand temperatures of up to 2000°F (1093°C) without losing their structural integrity. This makes them ideal for environments with extreme heat and thermal stress.
   • Corrosion Resistance: They offer excellent resistance to oxidation and corrosion, particularly in high-temperature, high-stress environments.
2. Incoloy Fasteners
   • Composition: Incoloy alloys generally contain nickel (up to 50%), chromium (up to 20%), and iron, with some variations that may include molybdenum, copper, and aluminum.
   • Temperature Resistance: Incoloy fasteners are more suited to moderate to high temperatures (up to 1500°F or 815°C), although they are still more resistant than many other alloys.
   • Corrosion Resistance: These alloys are resistant to oxidation and corrosion, especially in acidic environments. They are particularly effective in handling sulfide and chloride stress corrosion cracking.

Types of Inconel and Incoloy Fasteners

Both Inconel and Incoloy come in various forms depending on the specific needs of the application. Below are the most common types of fasteners made from these alloys:

Inconel Fasteners Types:

1. Inconel Bolts
   • Used in applications requiring high strength and resistance to extreme temperatures and oxidation.
2. Inconel Nuts
   • Commonly used in high-temperature environments, ensuring that the joint remains secure under stress.
3. Inconel Washers
   • Ideal for applications where resistance to thermal expansion and corrosion is critical.
4. Inconel Stud Bolts
   • These are widely used in industries such as aerospace, power plants, and chemical processing where high strength and corrosion resistance are vital.
5. Inconel Screws
   • These fasteners are used in precision machinery and high-performance engines.
6. Inconel Anchors
   • Often used in extreme environments where both high strength and corrosion resistance are necessary.

Incoloy Fasteners Types:

1. Incoloy Bolts
   • These bolts offer excellent resistance to corrosion, especially in acidic environments, and are often used in chemical processing plants.
2. Incoloy Nuts
   • Incoloy nuts are commonly used in environments exposed to high heat and corrosive elements, particularly in oil and gas industries.
3. Incoloy Washers
   • Provide superior performance in chemical environments where the alloy needs to resist both high temperatures and corrosive compounds.
4. Incoloy Stud Bolts
   • Used in applications in chemical plants, marine industries, and even nuclear power stations, where resistance to high-pressure and corrosive chemicals is required.
5. Incoloy Screws
   • Precision screws made from Incoloy alloys are used in equipment for chemical processing, as well as in heat exchangers.
6. Incoloy Flanges
   • Often found in piping systems in the oil and gas industries, Incoloy flanges offer resistance to corrosion and thermal cycling.

Key Characteristics Comparison

Applications of Inconel and Incoloy Fasteners

1. Inconel Fasteners
   • Aerospace Industry: Due to its exceptional resistance to heat and oxidation, Inconel is widely used in turbine blades, jet engines, and other high-temperature components.
   • Chemical Processing: Inconel fasteners are used in reactors, heat exchangers, and other equipment exposed to high temperatures and corrosive materials.
   • Power Generation: Inconel is also ideal for applications in nuclear reactors, gas turbines, and power plants where extreme conditions are the norm.
2. Incoloy Fasteners
   • Chemical Processing: Incoloy is often used in reactors, piping, and vessels that handle sulfuric acid, phosphoric acid, and other chemicals that can cause corrosion in metals.
   • Nuclear Power Plants: Due to its resistance to radiation and oxidation, Incoloy is commonly used in nuclear reactors and components exposed to radioactive materials.
   • Marine Applications: Incoloy fasteners are ideal for use in environments that are exposed to seawater, providing resistance against chloride-induced stress corrosion cracking.

Which One to Choose? Inconel or Incoloy?

Choosing between Inconel fasteners and Incoloy fasteners depends largely on the specific requirements of the application:

• If your application involves extremely high temperatures and you need superior strength and oxidation resistance, Inconel is the ideal choice.
• If you’re dealing with environments that require resistance to corrosion from acids or chlorides, but don’t need to withstand extreme temperatures, Incoloy fasteners are likely more cost-effective while still providing excellent performance.

Conclusion

Both Inconel and Incoloy fasteners offer unique benefits, and selecting the right alloy depends on factors like temperature resistance, corrosion resistance, and the specific conditions of your application. In general, Inconel is better for high-temperature and extreme heat environments, while Incoloy excels in moderately high temperatures with excellent corrosion resistance in aggressive chemical environments.

For applications that require top-notch performance in high-stress environments, both alloys provide critical reliability. By understanding the key differences and strengths of Inconel vs Incoloy fasteners, you can make an informed decision that best meets your needs.