When choosing a high-performance alloy to be used in demanding industrial applications, that are demanding Two names are often picked in the crowd: Inconel and Hastelloy. Both are nickel-based alloys made of nickel that have been designed to withstand extreme environments, high temperatures, corrosion, as well as mechanical stress. But the choice between them will depend on the operational conditions and requirements.

This guide by Tubotech Alloys Inc. examines Inconel vs. Hastelloy. It details the main differences in their properties as well as applications, and also addresses the crucial issue: Should you choose Inconel or Hastelloy for your needs?

What Is the Difference Between Inconel and Hastelloy?

The most significant distinction that separates Inconel and Hastelloy is their optimisation for various types of demanding environments.

Inconel is a family of nickel-chromium-based superalloys known particularly for excellent high-temperature strength, oxidation resistance, and corrosion resistance. Most popular grades include Inconel 600 601, 601, 625, 718, and 800-series alloys.

Hastelloy can be described as a nickel-based family of corrosion-resistant alloys that were developed specifically for harsh chemical environments. A number of Hastelloy grades have significant levels of molybdenum and chromium, giving outstanding resistance to corrosion, including localized crevice corrosion, pitting, and chemical damage.

In simple terms:

• Inconel: Most often, it is preferred when mechanical strength and high temperatures are key considerations.
• Hastelloy: Most often, it is preferred when severe corrosion from chemicals is the main issue.
• Both Excellent performance in conditions where stainless steel by itself may not be enough.

The performance of the alloy is contingent on the particular grade, and therefore comparing different alloys, not just alloy families, is essential.

Why Choose Inconel?

What is the reason Inconel is extensively utilized in the fields of aerospace, the power industry, chemical processing, and other highly demanding industries?

The answer is in the mixture that combines high-temperature strength of high temperatures, resistance to oxidation, as well as corrosion resistance.

Certain Inconel grades have significant mechanical strength even at high temperatures and are engineered to function in environments that require pressure, thermal cycling, and exposure to dangerous gases.

For instance, Inconel 625 offers good strength along with outstanding resistance to various corrosive environments, while Inconel 718 is widely acclaimed for its durability and ability to withstand high temperatures. applications.

The most common Inconel applications are:

• Aerospace engine components
• Gas turbines
• Heat exchangers
• Chemical processing equipment
• Nuclear power equipment
• Exhaust systems
• High-temperature furnace components
• Equipment for oil and gas

If your project involves high temperatures and mechanical load, Inconel can be the ideal choice.

Why Choose Hastelloy?

Why should you choose Hastelloy instead?

Hastelloy alloys are especially valuable when the equipment is exposed to highly corrosive substances. Their chemistry is engineered to stop corrosion mechanisms that could harm stainless steels of the conventional variety and other alloys.

A variety of Hastelloy grades have a significant amount of molybdenum, which is a major contributor to resistance to localized corrosion. Hastelloy C-series alloys, for example, are frequently used in demanding chemical processing environments.

The most common Hastelloy applications are:

• Chemical processing plants
• Equipment for controlling pollution
• Processing of pharmaceuticals
• Paper and Pulp industries
• Systems for treating waste
• Equipment for acid-processing
• Flue-gas desulfurization systems
• Extremely corrosive corrosion-related applications

Thus, if resistance to chemical corrosion is the main need, Hastelloy may provide the most effective solution.

Who Should Use Inconel or Hastelloy?

Designers, engineers, team members, procurement managers, and manufacturers must choose between these alloys based on their actual environment of service, not the name of the alloy or brand alone.

For instance, an aerospace engineer who has to deal with high temperatures and mechanical stress could prefer an appropriate Inconel grade. Chemical process engineers dealing with acidic substances may prefer an appropriate Hastelloy grade.

The final decision should be based on:

1. Operating temperature
2. Composition of chemicals in environment for service
3. Mechanisms for corrosion
4. Mechanical loads
5. Pressure
6. Requirements for Weldability
7. Method of Fabrication
8. Service life expectancy
9. Material availability
10. Cost of life for the entire cycle

This is the reason Hastelloy and Inconel must always be evaluated on a grade-by -grade basis.

When Should You Choose Inconel Over Hastelloy?

Choose the right Inconel grade if you need high-temperature mechanical strength, resistance to oxidation, or if the combination of heat and corrosion resistance is the primary requirement for the use.

For example, projects that require gas turbines and aerospace components, high-temperature processing equipment, as well as certain gas and oil systems may benefit from Inconel’s capabilities for high temperatures.

But, it doesn’t necessarily mean that Inconel is superior in all cases at higher temperatures, nor does it mean that Hastelloy is unable to handle temperatures that are high. The proper grade and the exact operating conditions affect performance.

When Should You Choose Hastelloy Over Inconel in the battle of choice between Hastelloy vs Inconel?

Hastelloy is typically the strongest choice when the machine is going to be exposed to extreme chemical attack, acids, chlorides, or other corrosive and aggressive media.

In the chemical processing environment, corrosion resistance may be more important than having the strongest possible mechanical strength in extreme temperatures. A dependable Hastelloy grade can therefore provide the best balance between durability and resistance to corrosion.

In addition, the exact chemical content and temperature, along with impurities, flow conditions, and exposure duration, must be taken into consideration prior to the final selection of materials.

Where Are Inconel and Hastelloy Used?

Each alloy family is utilized in industries where conventional metals can fail.

The best choice is based on the specifics of the service environment, and not the name of the company all by itself.

How Do You Choose Between Inconel and Hastelloy?

The best method is to start with the conditions of application.

Step 1: Identify the operating temperature. Determine normal, minimum, maximum, and transient temperatures.

2. Determine the corrosive environment.
   Check out the list of acids, alkalis, gases, chlorides and salts, as well as water, along with other substances that are in contact with the material.

Third step: Define the mechanical specifications.
Think about yield strength, tensile strength force and fatigue. Also, consider pressure, thermal cycling, and vibration.

Step 4: Determine fabrication requirements.
Forming, welding, machining, heat treatment, and dimensional requirements could determine the grade of material to be used.

Phase 5: Review lifecycle economics.
The price at which you pay the least doesn’t mean it’s the cheapest total cost. Materials that last longer and are less prone to the need for maintenance or replacement could be more valuable.

6. Contact material experts.
   For applications that require a lot of attention, consult with a seasoned alloy supplier as well as a materials engineer to determine the right grade and specifications.

Inconel vs Monel: How Does It Compare?

A similar one is Inconel against Monel.

Both are alloy families based on nickel. However, they’re made with different goals. Monel alloys consist of nickel-copper and are known for their excellent resistance to corrosion, especially in chemical and marine conditions.

Inconel alloys typically provide higher-temperature and high-strength capabilities, based on the grade.

Therefore:

• Inconel: An excellent candidate for applications with high temperatures and high strength.
• Hastelloy is a strong candidate to be used in extremely resistant chemical corrosion.
• Monel is a strong choice for certain chemical and marine areas where the nickel-copper alloy’s performance is ideal.

The decision should take into account the type of material and operating conditions.

Then, Inconel vs Hastelloy–which alloy should you pick?

There isn’t one universal winner.

Select Inconel when strength at high temperatures, as well as oxidation resistance and combined heat and corrosion performance, are top requirements. Select Hastelloy when resistance to extreme chemical corrosion is the main necessity.

In either case, choosing the right alloy is more crucial than just selecting an alloy type.

Tubotech Alloys Inc. can assist companies in evaluating high-performance alloy requirements and finding the most suitable materials for their applications. Always verify the grade of the material and applicable standards, measurements, as well as heat treatment and other conditions prior to ordering.

1. Is Inconel superior to Hastelloy?

There is no universally superior material. Inconel is usually preferred for strength at high temperatures and resistance to oxidation. Hastelloy is typically chosen for its extreme chemical corrosion resistance. The right choice will depend on the particular grade and the application.

2. What is the major difference between Hastelloy and Inconel?

The primary difference is their common style of design. Inconel grades are well-known for their strength at high temperatures and corrosion/oxidation resistance. Hastelloy grades are renowned for their resistance to chemical environments.

3. Is Hastelloy more resistant to corrosion than Inconel?

Certain Hastelloy grades offer superior resistance to certain chemical environments that are aggressive when compared to specific Inconel grades. However, the resistance to corrosion must be assessed based on the specific chemical concentration, temperature, and alloy grade.

4. Which is more suitable for high-temperature use, Inconel or Hastelloy?

A suitable Inconel grade is usually an excellent choice for projects which require high-temperature mechanical strength as well as resistance to oxidation. However, some Hastelloy grades are also able to perform at high temperatures. Your final selection is based on operational conditions.

5. How can you tell the differences between Inconel and Monel?

Inconel is primarily a nickel-chromium-based alloy family, while Monel is primarily a nickel-copper alloy family. Inconel is often chosen for extremely high-temperature and high-strength applications, whereas Monel is utilized in a variety of chemical and marine environments that require the performance of nickel-copper alloys.