Learn About The Uses Of Alloy 20 Pipes

Alloy 20 is a high-performance austenitic alloy composed of chromium and nickel in a chemical environment that is corrosion-resistant. In addition to sulfuric acid, it may also be subjected to a wide variety of hostile environments. A stabilizing component of the alloy is Niobium, which improves inter-granular corrosion resistance. A higher nickel-containing alloy, such as alloy 20, is usually more cost-effective while providing a better function compared to higher nickel-containing alloys.

Alloy 20 Pipes is a high alloy pipe resistant to corrosion caused by chloride and sulfuric acid. UNS N08020 is also known as alloy 20. Due to its copper content, the alloy provides high corrosion resistance across the board. In pickling equipment, process heat exchangers, pipework, and manufacturing tanks, stainless steel alloy is used frequently because of its resistance to crevice corrosion, pitting, and corrosion.

  • The key properties of alloy 20 fittings are their excellent mechanical properties:
  • Resulting in their suitability for manufacturing.
  • Materials that are acid resistant – nitric, phosphoric, and sulfuric acids.
  • Corrosion resistant to boiling sulfuric acid – cracking in boiling distilled water.
  • Highly resistant to corrosion, cracking, and crevice corrosion.

The fabrication process and the heat treatment process

Cold-work and hot-work processes can be used to manufacture alloy 20. To maintain a consistent temperature between 2100°F and 2250°F, hot forged material is subject to strict temperature control. Moreover, it ensures that the material temperature is not lower than 1800°F before forging. Heat the materials to 1725°F and 1850°F and anneal them for a minimum of 30 minutes per inch of thickness. Water-quench the material afterwards.

If stress-relieving is required, heating to below 1000°F followed by a water quench is recommended. Once a target temperature is reached, the water quench can be performed. For 30-minutes, Annealing Alloy 20 must be performed between 1725°F and 1850°F at a temperature of 1850°F per inch of thickness. Heat can be used to lower the hardness of an alloy by heating to 2100°F, however this can adversely affect the alloy’s stability.


Among the many industries using alloy 20, there are food processing, pharmaceuticals, maritime, petrochemicals, refinery, and chemical processing. Additionally, pumping equipment, screws and bolts, valves, fittings, cooking equipment, provocateurs, storage tanks, and mixing tanks are examples of how these products are put to use. As per ASME standards, these products can only be used at temperatures up to 1000°F. It is also imperative that the corrosion resistance required in a particular environment can be achieved.


Sulfuric acid is not likely to attack Alloy 20 pipes. It is also resistant to potassium nitrate, aqueous salt solutions, and phosphoric acid. Alloy 20 is a good choice when it comes to chloride stress corrosion cracking. Fissures and pitting are prevented, therefore it increases the durability. The corrosion rate might rise rapidly with chloride ions. Use extreme caution with these ions.

Learn About The Uses Of Alloy 20 Pipes

by Renine Metalloys time to read: 2 min