44 Facts About Alloy 20

What is Alloy 20?

Alloy 20, also known as Carpenter 20, is a nickel-iron-chromium alloy. It’s designed for maximum resistance to acid attack, especially sulfuric acid. This makes it a popular choice in various industries.

1. Alloy 20 contains 32-38% nickel, which provides excellent corrosion resistance.
2. It includes 19-21% chromium, enhancing its ability to withstand oxidizing environments.
3. The alloy has 2-3% molybdenum, which increases its resistance to pitting and crevice corrosion.
4. Copper content in Alloy 20 ranges from 3-4%, adding to its overall durability.
5. It also contains small amounts of niobium, which helps stabilize the alloy and prevent intergranular corrosion.

Applications of Alloy 20

Due to its unique properties, Alloy 20 is used in a variety of applications. These range from chemical processing to food and pharmaceutical industries.

6. Alloy 20 is commonly used in the production of sulfuric acid.
7. It’s also used in the manufacturing of pharmaceuticals, where purity and resistance to contamination are crucial.
8. The food industry uses Alloy 20 for equipment that comes into contact with acidic foods.
9. It’s employed in the production of plastics and synthetic fibers.
10. Alloy 20 is used in the manufacture of gasoline and other fuels.

Benefits of Using Alloy 20

The benefits of Alloy 20 make it a preferred material in many demanding environments. Its unique composition offers several advantages.

11. High resistance to sulfuric acid makes it ideal for chemical processing.
12. It offers excellent resistance to chloride-induced stress corrosion cracking.
13. The alloy has good mechanical properties at both ambient and elevated temperatures.
14. It’s easy to fabricate and weld, making it versatile for various applications.
15. Alloy 20 provides a cost-effective solution compared to other high-performance alloys.

Physical Properties of Alloy 20

Understanding the physical properties of Alloy 20 helps in selecting the right material for specific applications. These properties contribute to its performance in different environments.

16. Alloy 20 has a density of 8.08 g/cm³.
17. Its melting point ranges from 1357-1430°C.
18. The alloy has a thermal conductivity of 9.8 W/m·K.
19. It exhibits a specific heat capacity of 460 J/kg·K.
20. Alloy 20 has an electrical resistivity of 0.92 µΩ·m.

Mechanical Properties of Alloy 20

The mechanical properties of Alloy 20 are crucial for its performance in various applications. These properties determine its strength, flexibility, and durability.

21. Alloy 20 has a tensile strength of 620 MPa.
22. Its yield strength is 300 MPa.
23. The alloy has an elongation of 30% in 50 mm.
24. It exhibits a hardness of 217 HB.
25. Alloy 20 has a modulus of elasticity of 195 GPa.

Corrosion Resistance of Alloy 20

One of the standout features of Alloy 20 is its exceptional corrosion resistance. This makes it suitable for harsh environments.

26. Alloy 20 resists pitting and crevice corrosion in chloride environments.
27. It’s highly resistant to sulfuric acid, even at high concentrations.
28. The alloy withstands nitric acid and phosphoric acid.
29. It resists stress corrosion cracking in boiling 20-40% sulfuric acid.
30. Alloy 20 also shows good resistance to intergranular corrosion.

Fabrication and Welding of Alloy 20

Fabrication and welding are important considerations when working with Alloy 20. Its properties make it relatively easy to work with.

31. Alloy 20 can be easily welded using common welding techniques.
32. It’s suitable for both hot and cold working.
33. The alloy can be machined using standard methods.
34. It’s recommended to use carbide tools for machining Alloy 20.
35. Post-weld heat treatment is not usually required for Alloy 20.

Standards and Specifications of Alloy 20

Alloy 20 is produced according to various standards and specifications. These ensure its quality and suitability for different applications.

36. Alloy 20 is standardized under ASTM B463.
37. It’s also covered by ASTM B464.
38. The alloy meets the requirements of ASTM B366.
39. It’s included in ASTM B473.
40. Alloy 20 is specified under ASTM B462.

Common Forms of Alloy 20

Alloy 20 is available in various forms to suit different applications. These forms make it versatile for a wide range of uses.

41. Alloy 20 is available as sheets and plates.
42. It can be obtained in the form of bars and rods.
43. The alloy is also available as pipes and tubes.
44. Alloy 20 can be found in the form of fittings and flanges.

Alloy 20: The Essential Takeaway

Alloy 20 stands out for its corrosion resistance, especially against sulfuric acid. This makes it a top choice in industries like chemical processing and pharmaceuticals. Its nickel, chromium, and molybdenum composition provides durability and strength, ensuring long-lasting performance even in harsh environments.

Maintenance and fabrication are straightforward due to its weldability and machinability. This alloy's versatility extends to various applications, from storage tanks to heat exchangers.

Understanding these key facts about Alloy 20 helps in making informed decisions for industrial projects. Whether you're dealing with corrosive chemicals or need a reliable material for high-stress applications, Alloy 20 offers a robust solution.

Keep these points in mind when considering materials for your next project. Alloy 20's unique properties make it a valuable asset in many fields.