
UNS N08020 Pipes & Tubes, commonly identified as Alloy 20 or 20Cb-3, are nickel-iron-chromium alloy products developed for demanding chemical processing and acid-handling services. The composition of the grade is about 32–38% nickel, 19–21% chromium, 2–3% molybdenum and 3–4% copper with niobium as stabiliser. This combination offers excellent resistance to both sulfuric acid and chloride-related attack, crevice corrosion and pitting corrosion. The alloy 20 is very convenient when a standard stainless steel is not enough to offer the necessary corrosion resistance. To meet applicable ASTM specifications, seamless and welded pipes and tubes can be provided for process equipment and piping systems. Amardeep Steel manufactured and supplied UNS N08020 Pipes & Tubes for aggressive chemical and corrosive industrial applications.
Specifications of UNS N08020 Pipes and Tubes
Parameter | Details |
|---|---|
Grade | UNS N08020, Alloy 20, 20Cb-3, W.Nr 2.4660 |
Seamless pipe and tube | ASTM B729 / ASME SB729 |
Welded pipe | ASTM B464 / ASME SB464 |
Welded tube | ASTM B468 / ASME SB468 |
Electric fusion welded pipe | ASTM B474 / ASME SB474 |
Pipe sizes | 1/2" to 8" NB seamless, larger as welded; SCH 5S, 10S, 40S, 80S |
Tube sizes | 6.35 mm to 50.8 mm OD, 0.89 mm to 2.77 mm wall |
Condition | Stabilised annealed |
Ends | Plain end, bevelled end |
Length | Single random, double random, cut to length |
Certification | EN 10204 3.1, 3.2 with third party inspection on request |
Chemical Compositions of UNS N08020 Pipes and Tubes
Element | UNS N08020 (%) |
|---|---|
Nickel (Ni) | 32.0 to 38.0 |
Chromium (Cr) | 19.0 to 21.0 |
Molybdenum (Mo) | 2.0 to 3.0 |
Copper (Cu) | 3.0 to 4.0 |
Niobium + Tantalum (Nb + Ta) | 8 x C min, 1.00 max |
Carbon (C) | 0.07 max |
Manganese (Mn) | 2.00 max |
Silicon (Si) | 1.00 max |
Phosphorus (P) | 0.045 max |
Sulphur (S) | 0.035 max |
Iron (Fe) | Balance |
UNS N08020 Pipes and Tubes Mechanical Properties
Property (stabilised annealed, ASTM B729) | Value |
|---|---|
Tensile strength, min | 550 MPa (80 ksi) |
Yield strength (0.2% offset), min | 240 MPa (35 ksi) |
Elongation in 50 mm, min | 30% |
Physical Properties of UNS N08020 Pipes and Tubes
Property | Typical value |
|---|---|
Density | 8.08 g/cm³ (0.292 lb/in³) |
Specific heat (0°C to 100°C) | 500 J/kg·K |
Thermal conductivity (100°C) | About 13 W/m·K |
Mean thermal expansion (25°C to 100°C) | 14.7 µm/m·°C |
Modulus of elasticity | 200 GPa |
Magnetic permeability (annealed) | Below 1.02 (essentially non-magnetic) |
Equivalent Grades of UNS N08020 Pipes and Tubes
Standard | Designation |
|---|---|
UNS | N08020 |
Werkstoff Nr. | 2.4660 |
EN / DIN name | NiCr20CuMo |
Common names | Alloy 20, 20Cb-3, Carpenter 20 |
ASTM pipe / tube | B729 (seamless), B464 (welded pipe), B468 (welded tube), B474 (EFW pipe) |
Weight Chart of
NPS | OD (mm) | SCH 5S | SCH 10S | SCH 40S | SCH 80S |
|---|---|---|---|---|---|
1/2" | 21.34 | 1.65 mm / 0.82 kg/m | 2.11 mm / 1.03 kg/m | 2.77 mm / 1.31 kg/m | 3.73 mm / 1.67 kg/m |
3/4" | 26.67 | 1.65 mm / 1.05 kg/m | 2.11 mm / 1.32 kg/m | 2.87 mm / 1.73 kg/m | 3.91 mm / 2.26 kg/m |
1" | 33.40 | 1.65 mm / 1.33 kg/m | 2.77 mm / 2.15 kg/m | 3.38 mm / 2.58 kg/m | 4.55 mm / 3.33 kg/m |
1 1/4" | 42.16 | 1.65 mm / 1.70 kg/m | 2.77 mm / 2.77 kg/m | 3.56 mm / 3.49 kg/m | 4.85 mm / 4.59 kg/m |
1 1/2" | 48.26 | 1.65 mm / 1.95 kg/m | 2.77 mm / 3.20 kg/m | 3.68 mm / 4.16 kg/m | 5.08 mm / 5.57 kg/m |
2" | 60.33 | 1.65 mm / 2.46 kg/m | 2.77 mm / 4.05 kg/m | 3.91 mm / 5.60 kg/m | 5.54 mm / 7.70 kg/m |
2 1/2" | 73.03 | 2.11 mm / 3.80 kg/m | 3.05 mm / 5.42 kg/m | 5.16 mm / 8.89 kg/m | 7.01 mm / 11.75 kg/m |
3" | 88.90 | 2.11 mm / 4.65 kg/m | 3.05 mm / 6.65 kg/m | 5.49 mm / 11.62 kg/m | 7.62 mm / 15.72 kg/m |
4" | 114.30 | 2.11 mm / 6.01 kg/m | 3.05 mm / 8.61 kg/m | 6.02 mm / 16.55 kg/m | 8.56 mm / 22.98 kg/m |
6" | 168.28 | 2.77 mm / 11.64 kg/m | 3.40 mm / 14.23 kg/m | 7.11 mm / 29.09 kg/m | 10.97 mm / 43.81 kg/m |
8" | 219.08 | 2.77 mm / 15.21 kg/m | 3.76 mm / 20.55 kg/m | 8.18 mm / 43.79 kg/m | 12.70 mm / 66.53 kg/m |
UNS N08020 Pipes and Tubes Size Chart
Tube OD | 20 BWG (0.89 mm) | 18 BWG (1.24 mm) | 16 BWG (1.65 mm) | 14 BWG (2.11 mm) | 12 BWG (2.77 mm) |
|---|---|---|---|---|---|
1/2" (12.70 mm) | 0.27 kg/m | 0.36 kg/m | 0.46 kg/m | 0.57 kg/m | 0.70 kg/m |
5/8" (15.88 mm) | 0.34 kg/m | 0.46 kg/m | 0.60 kg/m | 0.74 kg/m | 0.92 kg/m |
3/4" (19.05 mm) | 0.41 kg/m | 0.56 kg/m | 0.73 kg/m | 0.91 kg/m | 1.14 kg/m |
1" (25.40 mm) | 0.55 kg/m | 0.76 kg/m | 0.99 kg/m | 1.25 kg/m | 1.59 kg/m |
1 1/4" (31.75 mm) | 0.70 kg/m | 0.96 kg/m | 1.26 kg/m | 1.59 kg/m | 2.04 kg/m |
1 1/2" (38.10 mm) | 0.84 kg/m | 1.16 kg/m | 1.53 kg/m | 1.93 kg/m | 2.48 kg/m |
2" (50.80 mm) | 1.13 kg/m | 1.56 kg/m | 2.06 kg/m | 2.61 kg/m | 3.38 kg/m |
Applications and Industrial Uses of UNS N08020 Pipes and Tubes
- Sulfuric Acid Processing Plants
- Chemical Process Piping Systems
- Acid Pickling Equipment
- Chemical Process Heat Exchangers
- Pharmaceutical Processing Equipment
- Explosives Manufacturing Plants
- Food and Synthetic Materials Processing
- Organic and Inorganic Chemical Plants
Frequently Asked Questions
What are UNS N08020 Pipes and Tubes?
UNS N08020 Pipes and Tubes are nickel-iron-chromium alloy products designed for corrosive chemical and acid-service applications.
What is UNS N08020 also known as?
UNS N08020 is also known as Alloy 20, INCOLOY Alloy 20, or 20Cb-3.
What ASTM standards cover UNS N08020 Pipes and Tubes?
Applicable standards include ASTM B729, B464, B468, B751, and B829, depending on the pipe or tube type.
Is UNS N08020 resistant to sulfuric acid?
Yes, UNS N08020 provides strong resistance to sulfuric acid, as well as pitting and crevice corrosion.
What is the difference between UNS N08020 and 316L?
UNS N08020 generally provides better resistance to sulfuric acid and certain aggressive chemical environments than 316L stainless steel.
Can UNS N08020 Pipes and Tubes be welded?
Yes, UNS N08020 can be welded using suitable welding procedures and compatible filler metals.
Does UNS N08020 require post-weld heat treatment?
Generally, no separate post-weld heat treatment is required for typical fabrication; the alloy is normally supplied in the annealed condition.
