ASTM B462 UNS N08020 Alloy 20 Flanges Manufacturer & Supplier
ASTM B462 UNS N08020 Alloy 20 weld neck flanges are nickel-iron-chromium alloy forged flanges designed for severe corrosive environments, particularly those involving sulfuric acid and acidic process media. Manufactured in accordance with ASTM B462 and dimensional standards ASME B16.5 / ASME B16.47, Alloy 20 flanges offer excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.
These flanges are widely used in chemical processing plants, petrochemical facilities, pharmaceutical industries, and acid handling systems
We are a leading manufacturer, supplier, and exporter of ASTM B462 UNS N08020 Alloy 20 Flanges, engineered for superior resistance against sulfuric acid, phosphoric acid, and chloride stress corrosion cracking. Known as Alloy 20, Carpenter 20, or 2.4660, this nickel-iron-chromium alloy with copper and molybdenum additions is widely used in the chemical, pharmaceutical, food processing, and marine industries.
What Is ASTM B462?
ASTM B462 is the standard specification for nickel alloy forgings, including flanges, fittings, valves, and pressure-retaining components. The standard defines requirements for:
- Chemical composition
- Mechanical properties
- Heat treatment
- Testing and inspection
ASTM B462 ensures consistent quality and performance of nickel-based alloys such as UNS N08020 (Alloy 20) in aggressive chemical environments.
Material Grade: UNS N08020 (Alloy 20)
UNS N08020, commonly known as Alloy 20, is a nickel-based alloy originally developed for sulfuric acid service. It contains chromium, molybdenum, copper, and niobium, providing excellent corrosion resistance across a wide range of chemical media.
UNS N08020 Flange Standards & Dimensions
- Standard: ASTM B462 / ASME SB462
- Size Range: ½” to 48” (DN15 – DN1200)
- Pressure Class: 150, 300, 600, 900, 1500, 2500 LB
- Facing Types: RF (Raised Face), FF (Flat Face), RTJ (Ring Type Joint)
- Dimension Standards: ASME B16.5, ASME B16.47, MSS-SP-44
Types of Alloy 20 Flanges:
- ASTM B462 N08020 Weld Neck Flange (WN)
- ASTM B462 N08020 Slip On Flange (SO)
- ASTM B462 N08020 Blind Flange (BLRF)
- Socket Weld Flange (SW)
- Lap Joint Flange (LJ)
- Threaded Flange (TH)
- Ring Type Joint Flange (RTJ)
- Long Weld Neck Flange (LWN)
Chemical Composition of N08020
| Element | Wt, % |
|---|---|
| Carbon [C] | ≤0.07 |
| Manganese [Mn] | ≤2.00 |
| Phosphorus [P] | ≤0.045 |
| Sulfur [S] | ≤0.035 |
| Silicon [Si] | ≤1.00 |
| Nickel [Ni] | 32.00~38.00 |
| Chromium [Cr] | 19.00~21.00 |
| Molybdenum [Mo] | 2.00~3.00 |
| Copper [Cu] | 3.00~4.00 |
| Niobium+Tantalum [Nb+Ta] | 8xCarbon~1 |
| Iron | Remainder |
*The tabulated values are abstracted from ASTM B462 Gr. UNS N08020.
Mechanical Properties of N08020
| Alloy | Tensile Strength, min. | Yield Strength, min. | Elongation, min. | Reduction of Area, min. | ||
|---|---|---|---|---|---|---|
| ASTM B462 | ksi | MPa | ksi | MPa | % | % |
| UNS N08020 | 80 | 551 | 35 | 241 | 30.0 | 50.0 |
*All values shall be measured at room temperature.
*Alloy 20 flanges shall be supplied in stabilized-annealed condition.
Benefits of our N08020 flanges
- Excellent resistance to sulfuric acid and chloride stress corrosion cracking
- High mechanical strength and toughness
- Versatile across chemical, petrochemical, food, and pharmaceutical industries
- Suitable for marine and offshore applications
We provide Alloy 20 flanges with mill test certificates (EN 10204 3.1/3.2), NDT, PMI, and full traceability. Our products are exported globally to industries requiring high-performance corrosion-resistant flanges.
ASTM B462 UNS N08020 Alloy 20 weld neck flanges provide excellent corrosion resistance, mechanical reliability, and long service life in acidic chemical processing environments. Fully compliant with ASTM B462 and ASME flange standards, Alloy 20 forged flanges are a proven solution for sulfuric acid and corrosive process systems.
Download ASTM B462 N08020 Flange specification
