Hastelloy vs Inconel: The Key Difference - Knowledge

Inconel and Hastelloy are both nickel-chromium-molybdenum-based alloys. The key difference between the two types of superalloys is their specific corrosion resistance properties.

Hastelloy is a compound that can resist corrosion whereas Inconel is not suitable for severely corrosive environments. Hastelloy also has more molybdenum content than Inconel, although Inconel has a higher level of chromium concentration.

Both compound alloys are suitable for different projects and workpieces due to their varied compounds.

1.Applications in Different Industries

Inconel Applications

Ideal use for oil and gas industries

Inconel can have many applications and is commonly used for propeller shafts, hot vessels for food and water, chemical processing equipment, gas turbines, aircraft, and tank trucks.

Hastelloy Applications

Hastelloy is commonly used for pipes, and valves in chemical processing, petrochemical industries, nuclear reactors, pressure vessels and heat exchangers.

2.Composition Variances & Alloying Elements

Composition variances and alloying elements play a crucial role in determining the properties and performance of high-performance alloys such as Hastelloy and Inconel. These elements are carefully selected and combined in specific proportions to achieve desired characteristics such as corrosion resistance, high temperature strength, and durability. Understanding the differences in composition and alloying elements between Hastelloy and Inconel is essential for selecting the most suitable alloy for a particular application.

Inconel

Inconel alloys are known for their excellent mechanical properties such as being highly resistant to oxidation and corrosion which makes them an ideal material in harsh environments where materials are at risk of degradation.

Inconel has high tensile strength, fatigue resistance, and toughness due to its class of nickel-chrome-based superalloys.

Inconel can withstand elevated temperatures and corrosive environments which is why they are used in a wide range of applications including aerospace, chemical processing, marine engineering, and nuclear reactors.

Hastelloy

Hastelloy is a category of nickel-based superalloys containing molybdenum. Nickel has a good high-temperature resistance to the alloy. Chromium and molybdenum give the alloy corrosion resistance.

Additionally, Hastelloy alloys have excellent mechanical strength and are highly resistant to oxidation and cracking. These properties make Hastelloy a popular choice for applications in industries such as chemical processing, aerospace, and marine engineering.

The various grades of Hastelloy offer different levels of resistance to specific corrosive environments, such as oxidising acids, reducing acids, and seawater. For example, Hastelloy C276 (a Nickel-chromium-molybdenum wrought alloy), is known for its outstanding resistance to a wide range of corrosive chemicals.

Overall, Hastelloy alloys are known for their versatility, durability, and reliability in challenging environments, making them a preferred choice for critical applications where resistance to corrosion and high temperatures are essential.

3.Corrosion Resistance Comparison

Both Hastelloy and Inconel alloys offer comparable corrosion-resisting benefits. However, Inconel has a small advantage when used in oxidising applications. However, as it is more molybdenum-forward, Hastelloy offers better performance when subjected to reducing corrosion.

4.Temperature and Pressure Capabilities

Inconel can withstand temperatures of 1800-2000 degrees Fahrenheit. They provide good oxidation resistance and exceptional fatigue strength.

Hastelloy is also a strong alloy with great oxidation resistance like Inconel. However, it can withstand higher temperatures of up to 2200 degrees Fahrenheit.

5.Cost Considerations

The proportion of Hastelloy's composition (nickel, chromium, molybdenum and other trace elements) and the purity of raw materials used will significantly impact the cost.
Additional factors like specialised manufacturing processes, rigorous quality control, and limited production capacity will also contribute to the costs of Inconel.