Inconel: Definition, Types, Properties, and Applications

There are various nickel alloys and superalloys that are used in different applications. Whenever the discussion of these alloys comes, Inconel is also a highlight. It is commonly used as a superalloy in various applications. Hence, if you are planning to use it, having an insight into its properties, types, and applications is a must.

The article below features detailed information on Inconel alloys, so let's read!

What is Inconel?

Inconel alloys are widely used in environments that are equipped with high temperatures and have an extreme impact on oxidation and corrosion. The Inconel material is resistant to such environments and is suitable for harsh surroundings.

They are widely used in chambers where chemical reactions and processing take place, oil fields, marine applications, gas turbines, etc.

The Inconel alloy is generally made using steel, iron, nickel, and some others constituting titanium, molybdenum, and copper. These alloys offer abrasion resistance, better weldability, and are robust.

What is Inconel Made of?

The actual initial Inconel alloy was Inconel 600, it comprises more than 72% of nickel, around 6 to 10% of iron, 14 to 17% of chromium, and some copper, sulfur carbon, and magnesium traces.

The constituents of the Inconel may vary in terms of proportions and some of the Inconel alloys may also contain titanium, molybdenum, aluminum, cobalt, etc.

How is Machining with Inconel?

Inconel is not very easy when it comes to its machining, however, it requires good tooling so that the results achieved are optimum, and also when cut depths are moderate, maintenance becomes easier. Some of the Inconel machining tips comprise the following:

• The Inconel material is hard and therefore you must keep an eye on the wear and tear of tools.
• Cermet tips are suitable for consistent cutting.
• In order to achieve a smooth chip flow, make sure to continue the feed rather than stopping and starting again and again during the drilling process.
• In high-performance milling cutters, four and five-flute variable helix is suggested for use.

Different Types of Inconel

There are various types of Inconel alloys and some of these are given below.

Inconel 600

Inconel 600 is the original Inconel alloy, it offers corrosion resistance and is suitable for environments with extreme temperatures. Inconel 600 is suitable for chemical plant components and offers a robust strength of 650 degrees.

Inconel 601

Inconel 601 offers seamless resistance against oxidation. It is also suitable for elevated temperatures and comprises excellent mechanical properties. It is even equipped with better stress corrosion and doesn't crack easily. Inconel 601 consists of low carbon and has a fine grain structure which offers crack resistance.

Inconel 625

Inconel 625 has improved corrosion resistance compared to Inconel 601 and Inconel 600. Its performance is also improved and it retains strength for a maximum of 980 degree centigrade.

Inconel 718

Inconel 718 is suitable for precipitation hardening, it comprises sufficient toughness to withstand a maximum temperature of 650 degrees centigrade and offers resistance against oxidation and corrosion.

Inconel X-750

Inconel X-750 is equipped with excellent strength, corrosion, and oxidation resistance for temperatures up to 980 degrees centigrade. It is commonly used in gas turbines and aerospace applications.

Inconel 690

Inconel 690 offers resistance against chloride corrosion, it is also capable of handling high temperatures, water stress, and oxidation. It is commonly used in environments subjected to nitric acid, nuclear water treatment plants, and steam generators.

Inconel 792

Inconel 792 has a high content of aluminum which helps to offer high corrosion and temperature resistance. It is ideal for combustion chambers and gas turbine applications.

Properties of Inconel

Inconel is a super alloy that is known for its resistance against oxidation, and corrosion and offers high strength, apart from these some of the other properties of Inconel are as follows:

• Inconel can maintain high strength and stability at high temperatures.
• It resists corrosion and oxidation and hence is suitable for harsh environments that are exposed to high pressure and aggressive chemicals.
• Inconel has high tensile and rupture strength which makes it suitable for all such applications that need durability.
• Inconel is hard to machine but still can be welded using different techniques and needs specific tools to meet its toughness.

Applications of Inconel

There are various applications of Inconel some of these comprise the following:

Aerospace

In the aerospace industry, Inconel is used in turbine engines and rocket motors. In turbine engines, it is used for manufacturing turbine blades and combustors so that they can withstand high temperatures and mechanical strength.

In rocket motor components subjected to high temperature are manufactured using Inconel and the ones that need resistance against oxidation.

Chemical Industry

In the chemical industry heat exchangers are equipped with Inconel to handle corrosive fluids. Pressure vessels and chemical plant equipment also have components like pipes and valves made using Inconel to resist aggressive chemicals.

Power Generation

The power generation sector comprises gas turbines and nuclear reactors, the Inconel is used in combustors, steam generators, and core components of the nuclear reactors as they operate at high temperatures and need corrosion resistance.

Medical

Inconel is known for its strength and biocompatibility hence is suitable for various medical implants. Surgical instruments requiring high strength are also manufactured using Inconel.

Electronics

Electronic devices need non-magnetic materials that are temperature resistant and Inconel comprises these properties. Also, thermocouples and other high-temperature sensing devices use Inconel in their construction.

What are the Advantages of  Inconel?

There are various advantages of Inconel and some of these are given below:

• It offers high-temperature stability and hence retains its strength even when subjected to extreme temperatures.
• Inconel forms a layer of oxide that is stable enough to protect it from oxidation and also can withstand corrosive environments resisting corrosion.
• It is a versatile material that can be welded and machined using specialized techniques to manufacture complex components.
• Inconel alloys offer non-magnetic properties which are required in various applications like electronics where magnetic interferences need minimization.
• Inconel withstands exposure to harsh chemicals like salts, alkalies, and acids.
• It is a durable and biocompatible material that is suitable for the medical industry too.

What are the Limitations of  Inconel?

Despite being a very suitable material, Inconel also has some limitations given as follows:

• Inconel is an expensive alloy because it has a high content of nickel and it also has a complex process of manufacturing.
• Inconel is tough and resistant to deformation which leads to difficulty in machining it. Hence, Inconel needs specialized equipment and cutting tools that offer precise control over the speed of cutting.
• Inconel alloy is not very commonly available and hence has a limited supply, it is usually manufactured and is reserved for critical applications.

Common FAQs about Inconel

How Strong is the Inconel Material?

The hardness of Inconel varies depending on the way it is processed. Inconel which is cold-rolled will have a different hardness compared to the annealed one.

What is the Corrosion Resistance of Inconel Alloys?

Inconel is known for its corrosion resistance in all types of environments, they even offer strong corrosion resistance in elevated temperatures, nitric acid, fluorinated atmospheres, and even combustion-oriented environments.

What is the Difference Between Inconel and Titanium?

Inconel 718 offers a tensile strength of 1375 MPa, whereas the titanium alloy has a strength of 1170 MPa. Inconel offers higher strength.

What is the Difference Between Inconel and Stainless Steel?

Inconel is better than stainless steel at high temperatures in terms of its resistance against corrosion.

Conclusion

Inconel is used widely in multiple applications, it is adopted mostly because of its seamless properties like its robustness, corrosion resistance, precise formability, etc when exposed to harsh environments.

If you are looking for CNC machining Inconel services, you can get in touch with DEK and have hands-on affordable and high-quality services for Inconel making that are suitable for various applications.