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What are the Uses of Alloy 20 Pipe?

Alloy 20 is a chromium-iron-nickel-based, austenitic alloy that comes with excellent corrosion resistance in chemical environments. It contains sulfuric acid and many aggressive media well. The alloy is stabilized with niobium that helps it to resist intergranular corrosion. Alloy 20 can help provide potential cost savings compared to the higher nickel-based alloys as it outperforms standard stainless steel.

More about Alloy 20 pipe

Alloy 20 are commonly known as UNS N08020, is a high alloy pipe made of unique stainless steel grade with excellent resistance to the chloride and sulfuric acid stress corrosion cracking. The alloy contains copper content that helps in providing excellent general corrosion resistance. Due to its resistance to pitting, crevice corrosion, and corrosion, the stainless steel alloy is widely used for manufacturing pickling equipment, process piping, heat exchangers, and manufacturing tanks.

Alloy 20 pipe fittings, Alloy 20 flanges, and other Alloy 20-grade products are helpful in various applications throughout the chemical process industry, paper manufacturing, industrial heating equipment, plastics, synthetic rubber, pharmaceuticals, and chemical process industry.

Key Properties of Alloy 20 fittings

Excellent mechanical properties

Highly suitable for fabrication

Excellent resistance to other acids – nitric and phosphoric acids

Strong resistance to stress corrosion – cracking in boiling 20 to 40% sulfuric acid

Good resistance to pitting, crevice corrosion, and corrosion

Uses of Alloy 20 Pipe:

Applications and Industries

The uses of Alloy 20 are in a variety of industries such as food processing, pharmaceutical, marine, petrochemical, refining, and chemical processing. The end use of applications also includes pumps and valves, fasteners, food processing equipment, fittings, agitators, mixing tanks, and storage tanks.

Applications are limited to the maximum temperature of 1000°F per ASME. It is also essential to determine if you could achieve the necessary corrosion resistance within the given environment.

Corrosion Resistance

Alloy 20 comes with good resistance to sulfuric acid. It also shows a suitable resistance in the aqueous salt solution, nitric acid, and phosphoric acid. Alloy 20 comes with an excellent option if chloride stress corrosion cracking is the problem. The reason is that it helps in resisting the crevice and pitting which increases durability. You must be cautious with chloride ions because the corrosion rate can increase significantly over time.

Heat treatment and fabrication

Alloy 20 can be formed either by cold-work or hot-work using traditional methods. Hot forged material needs heating between 2100°F and 2250°F with careful temperature control. It also ensures that the material does not fall below 1800°F before forging. After hot working, anneal the materials by heating to 1725°F and 1850°F for a minimum of 30 minutes per inch of thickness followed by water quench.

When there is a requirement of stress-relieving, heat the temperature below 1000°F and follow up with a water quench. It can happen after the desired time when a specific temperature gets established. Annealing Alloy 20 must be between 1725°F and 1850°F for 30 minutes at temperature per inch of thickness. You can obtain lower hardness by heating to 2100°F, but this may harm the stabilization of the alloy.

Alloy 20 Pipe Fittings Grade and Specifications

Stainless SteelTradenameUNS No.Werkstoff No. 

Density (g/cm3)


Alloy 20Incoloy Alloy 20, Carpenter 20N080202.46608.083

Alloy 20 Pipe Fittings Production Range

SpecificationsASTM B366, ASTM SB 366, ASTM B564, ASME SB564
GradeAlloy 20, UNS N08020, 2.4660, Incoloy Alloy 20, Carpenter 20
TypeSeamless / Welded / Fabricated
Bending RadiusR = 1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom
Range½ “NB to 24 “NB in Sch 10s, 40s, 80s, 160s, XXS
DimensionsANSI / ASME B16.9, B16.28, MSS-SP – 43

Alloy 20 is a popular choice in a lot of industries. It is useful in extreme situations that include heat exchangers, mixing tanks, metal cleaning, and pickling equipment, and piping.


We hope that with the help of this guide, you understand some of the primary uses of Alloy 20 Pipe and Alloy 20 Flanges. Texas Flange is subject to strict inspection at each stage of the production process, from starting material purchase to product dispatch. They are visually examined for conformity to ASTM, ASME, MSS, DIN, EN, and JIS standards and codes.

If you want any specific flange information, get in touch with us today!

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