ASTM B729 UNS N08020 Seamless Pipe

UNS N08020 Alloy 20 Tube is also known as Carpenter 20 or by its trade name UNS N08020. Developed to exhibit good corrosion resistance, Carpenter alloy is an alloy with excellent resistance to sulfuric acid. This alloy is stabilized with niobium to resist intergranular corrosion. Alloy 20 can offer potential cost savings compared to higher nickel-based alloys while outperforming standard stainless steels. It has good mechanical properties and can be manufactured relatively easily. Although the alloy was designed for sulfuric acid related industries, it is widely used throughout the chemical processing industry. It is also used to process pharmaceuticals, food, gasoline, solvents, plastics, explosives, synthetic fibers and many other products.

The most commonly used standard for Alloy 20 seamless pipes is ASTM B729. This specification covers seamless pipes that are designed for general corrosion-resisting and low or high-temperature service. Other standards include ASTM B464, ASTM B468, and ASTM B474.

The manufacturing process for Alloy 20 seamless pipes involves a rigorous inspection process to ensure the highest quality. The pipes are made by using the extrusion process, where a heated billet is forced through a die to form a tube. The tubes are then cold-drawn to achieve the desired dimensions. The pipes are subject to various testing and inspection procedures, including visual inspection, ultrasonic testing, eddy current testing, and hydrostatic testing.

UNS N08020 Alloy 20 seamless pipes Chemical Composition

The physical properties of Alloy 20 seamless pipes

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  Density: 8.05 g/cm3

  
  

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  Melting point: 1443 – 1448°C

  
  

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  Thermal conductivity: 12.9 W/(m.K)

  
  

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  Specific heat capacity: 446 J/(kg.K)

  
  

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  Electrical resistance: 1.25 x 10-6 Ω.m

  
  

Alloy 20 seamless pipes are widely used in the chemical processing industry due to their superior corrosion resistance and excellent mechanical properties:

1. Manufacture of equipment for sulfuric acid production.

2. In the production of gas scrubbers and cleaning systems.

3. In the manufacture of heat exchangers for chemicals and petrochemicals.

4. In the manufacture of tanks, pipes, pressure vessels, and reactors for chemical processing, pharmaceuticals, and food processing.

5. In marine applications for the construction of boat and ship hulls and propeller shafts.

UNS N08020 Alloy 20 is an austenitic stainless steel that is highly resistant to pitting, corrosion, and acidic environments. Its unique properties make it ideal for use in industries such as chemical processing, pharmaceuticals, food and beverage, and water treatment. Alloy 20 seamless pipes are manufactured in accordance with standard specifications and are widely available in the market.