All You Need to Know: Cupronickel and Hastelloy Steel Grades

Published on 19 September, 2024

For industries like marine engineering, petrochemical, chemical processing, or aerospace, where materials are exposed to extreme conditions, understanding steel grades ensures the longevity and reliability of structures, machinery, and piping systems. Different grades offer unique combinations of strength, corrosion resistance, temperature tolerance, and other key factors that directly influence their suitability for various environments. 

 

What are Steel Grades?

 

Steel grades are classifications based on the properties of the metal and its alloying elements. For Cupronickel and Hastelloy, grades are determined by their composition, mechanical strength, and resistance to corrosion, oxidation, and temperature. 

 

Cupronickel Grades: Marine-Grade Material for Extreme Conditions

 

Cupronickel (Cu-Ni) is an alloy primarily made of copper and nickel. It contains trace elements such as iron and manganese to boost its corrosion resistance, particularly in seawater.

 

Grades of Cupronickel:

 

1. Cupronickel 90/10 (C70600):

• Composition: 90% copper and 10% nickel.

• Properties: High corrosion resistance in seawater, good thermal conductivity.

• Applications: Marine hardware, desalination plants, and heat exchangers.

 

2. Cupronickel 70/30 (C71500):

• Composition: 70% copper and 30% nickel.

• Properties: Greater strength and corrosion resistance than 90/10, especially in high-velocity seawater.

• Applications: Offshore oil and gas platforms, seawater cooling systems, and condensers.

 

Key Properties of Cupronickel Grades:

 1. Corrosion Resistance: Both 70/30 and 90/10 grades are resistant to biofouling and seawater corrosion.

 2. Mechanical Strength: 70/30 offers higher mechanical strength than 90/10.

 3. Thermal Conductivity: Both grades provide excellent thermal conductivity, making them ideal for heat exchangers and piping systems.

 

Hastelloy Steel Grades: Superalloys for Extreme Chemical Resistance

 

Hastelloy is a superalloy made of nickel, molybdenum, and chromium. It’s known for its ability to withstand extreme conditions, such as exposure to aggressive chemicals, high temperatures, and oxidation.

 

Common Grades of Hastelloy:

 

1. Hastelloy C-276:

• Composition: High nickel, molybdenum, and chromium content with a small amount of tungsten.

• Properties: Exceptional resistance to a wide range of severe chemicals and oxidizing agents.

• Applications: Petrochemical industry, chemical processing, pollution control, and pulp and paper production.

 

2. Hastelloy B-3:

• Composition: High nickel and molybdenum with limited iron content.

• Properties: Excellent resistance to hydrochloric acid at all temperatures and concentrations.

• Applications: Chemical reactors, distillation equipment, and piping systems in petrochemical and chemical industries.

 

Key Properties of Hastelloy Grades:

 

1. Corrosion Resistance: Hastelloy alloys can withstand acidic environments that would corrode most other materials.

2. High-Temperature Stability: Hastelloy maintains its strength and resistance at high temperatures, making it ideal for industries with extreme heat and corrosive conditions.

3. Oxidation Resistance: It resists oxidation in both static and dynamic conditions, raising its longevity in industrial settings.

 

Comparing Cupronickel and Hastelloy Steel Grades

 

Though both Cupronickel and Hastelloy are known for their durability, they serve different industries based on their distinct properties.

 

	Cupronickel 90/10 & 70/30	Hastelloy C-276 & B-3
Corrosion Resistance	Excellent in seawater	Exceptional in aggressive chemicals
Temperature Tolerance	Moderate	High (up to 1000°C for some grades)
Applications	Marine, Oil & Gas	Chemical processing, aerospace

 

Understanding the role of advanced alloys of best steel grades and classifying between them accordingly like Cupronickel or Hastelloy and Inconel 600 or Monel Fasteners helps businesses make informed decisions. Choosing the right alloy guarantees your application is protected, reduces costs, and improves performance, even in tough environments. 

 

At Online Fittings, we offer a comprehensive range of Cupronickel and Hastelloy steel grades, ensuring you get the best material for your industrial needs. Explore our products today to find the perfect solution for your next project!