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Alloy 20 Sheets & Plates Supplier in Mumbai, India – ASTM B463 UNS N08020
Nicorex Alloys is an ISO 9001 / ISO 14001 certified supplier of Alloy 20 sheets and plates based in Mumbai, India. Alloy 20 (UNS N08020, Werkstoff 2.4660), also known as Carpenter 20, Carpenter 20Cb-3®, and Alloy 20, is a nickel-iron-chromium austenitic flat product manufactured to ASTM B463 / ASME SB463.
The nominal balance of Ni 32–38%, Cr 19–21%, Mo 2–3%, Cu 3–4%, and Nb 8×C min–1.0% gives this alloy specific resistance to sulfuric acid, phosphoric acid, and chloride stress corrosion cracking. Copper at 3–4% provides the sulfuric acid protection that separates Alloy 20 from standard austenitic stainless steels. Niobium stabilises the matrix against sensitisation, preserving intergranular corrosion resistance in as-welded plate joints. Alloy 20 is utilised across a vast spectrum of heavy industries where localised corrosion, such as pitting and crevice corrosion, or chloride-induced stress corrosion cracking, can cause major damage to a structure.
We supply Alloy 20 sheets and plates in a wide size range. Sheet thickness is 0.5–4.76 mm and plate 4.76–120 mm, with widths from 1000–2500 mm. Sheet lengths go up to 6000 mm and plate up to 12,500 mm. It is available as hot rolled plate, cold-rolled sheet, strip, coil, foil, shim, perforated sheet, chequered plate, circles, rings, and clad plate. Material is stabilised-annealed at 982–1010°C, non-magnetic, and suitable for service up to 538°C. It is supplied with EN 10204 3.1 mill test certificates, PMI results, and full traceability.
Alloy 20 Sheet & Plate Specifications
Here are the specifications for Alloy 20 sheets and plates to understand our product better.
| Standard | ASTM B463 / ASME SB463 |
|---|---|
| Sheet Thickness | 0.5 to 4.76 mm |
| Plate Thickness | 4.76 to 120 mm |
| Width | 1000, 1250, 1500, 2000, 2500 mm |
| Condition | Stabilize-Annealed (982–1010°C / 1800–1850°F) |
| Hardness | ≤217 HB / 95 HRB |
Alloy 20 vs Alloy 825 - Which to Specify for Acid Service?
| Feature | Alloy 20 | Alloy 825 |
|---|---|---|
| Alloy Type | Ni-Fe-Cr austenitic alloy | Ni-Fe-Cr austenitic alloy |
| Nickel (Ni) Content | ~32–38% | ~38–46% (≈42% typical) |
| Molybdenum (Mo) | ~2–3% | ~2.5–3.5% (≈3% typical) |
| Copper (Cu) | 3–4% (enhances sulfuric acid resistance) | ≤3% |
| Stabilization | Nb-stabilised | Ti-stabilised |
| Best For | Dilute H₂SO₄ (20–40%) service | Broad acid service & high-temp chloride environments |
| Cost Efficiency | Generally lower cost | Typically higher cost |
Chemical Composition of Alloy 20 Sheets & Plates per ASTM B463
Nickel, chromium, copper, molybdenum, and niobium define Alloy 20’s corrosion profile. Composition per ASTM B463 for UNS N08020:
| Nickel (Ni) | Chromium (Cr) | Copper (Cu) | Molybdenum (Mo) | Niobium + Tantalum (Nb+Ta) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Sulphur (S) | Phosphorus (P) | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|---|---|
| 32.00 – 38.00 | 19.00 – 21.00 | 3.00 – 4.00 | 2.00 – 3.00 | 8×C min – 1.00 max | 0.07 max | 2.00 max | 1.00 max | 0.035 max | 0.045 max | Balance |
Nb stabilises against sensitisation and intergranular corrosion in as-welded joints. Cu at 3–4% drives sulfuric acid resistance, the primary reason Alloy 20 sheets are specified for acid tank linings and reactor cladding.
Mechanical Properties of Alloy 20 Sheet & Plate (Stabilise-Annealed)
The mechanical properties of Alloy 20 sheet and plate in the stabilised-annealed condition, as per ASTM B463.
| Tensile Strength (min) | Yield 0.2% Offset (min) | Elongation (min) | Hardness (max) |
|---|---|---|---|
| 551 MPa (80 ksi) | 241 MPa (35 ksi) | 30% | 217 HB |
The 551 MPa tensile / 30% elongation combination suits ASME Sec. VIII pressure vessels and allows cold forming of sheets for acid equipment linings.
Physical Properties of Alloy 20 Sheets & Plates
The physical properties of Alloy 20 (UNS N08020) highlight its stability and performance in demanding environments.
| Density | Melting Range | Elastic Modulus | Thermal Conductivity (20°C) | Thermal Expansion (20–100°C) | Magnetic |
|---|---|---|---|---|---|
| 8.08 g/cm³ (0.292 lb/in³) | 1350–1430°C (2475–2607°F) | 193 GPa (28.0 × 10⁶ psi) | 12.1 W/m·°C | 15.0 µm/m/°C | Non-magnetic (paramagnetic) |
Thermal conductivity is roughly 30% of carbon steel. Use lower heat input during welding to control distortion on large plates.
Equivalent Designations for Alloy 20
Alloy 20 is recognised internationally under multiple equivalent designations and standards, ensuring global acceptance and material traceability.
| UNS | Werkstoff Nr. | EN / DIN | JIS | GOST | BS |
|---|---|---|---|---|---|
| N08020 | 2.4660 | NiCr20CuMo (DIN 17744) | NCF 20 | ХН32МДБ | NA1 |
Premium Industrial Materials
Get Alloy 20 Sheets & Plates at Competitive Prices
Available Forms of Alloy 20 Flat Products
Nicorex Alloys stocks Alloy 20 flat products:
Alloy 20 Hot Rolled Plates
Alloy 20 Cold Rolled Sheets
Alloy 20 Strips
Alloy 20 Perforated Sheets
Alloy 20 Chequered Plates
Alloy 20 Coils
Alloy 20 Foils
Alloy 20 Shim Sheets
Corrosion Resistance of Alloy 20 Sheets & Plates
Alloy 20 was developed for sulfuric acid service. Cu at 3–4% provides specific protection in dilute H₂SO₄ across 20–40% concentration at boiling conditions. Plates and sheets also resist phosphoric acid (wet-process and thermal), nitric acid, and acetic acid. Max service: 538°C (1000°F) per ASME guidelines.
Ni at 32–38% gives strong chloride SCC resistance, where 304/316 SS fail. PREN sits around 27–31, depending on exact composition. Nb stabilisation prevents intergranular corrosion in welded plate joints. Alloy 20 serves as a cost-effective alternative to Alloy 825 or Hastelloy C-276 in moderate acid environments. Not recommended for H₂SO₄ above 60% at elevated temperature; evaluate higher-grade alloys using isocorrosion data.
Industrial Applications of Alloy 20 Sheets & Plates
For its corrosion resistance and strength, many industries rely on Alloy 20 sheets to ensure a smoother and well-functioning structure.
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Chemical Processing: Reaction vessels, acid tanks, condenser plates for H₂SO₄ and H₃PO₄.
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Sulfuric Acid Production: Acid coolers, absorption towers in contact acid plants.
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Fertiliser: Phosphoric acid evaporators and nitric acid piping.
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Oil & Gas: FGD linings, gas scrubbing towers, deaerator vessels.
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Marine & Desalination: Seawater heat exchanger tubesheets and offshore cladding.
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Pulp & Paper: Bleach plant equipment and ClO₂ generators.
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Pharma & Food: BA-finish vessels for hygienic acid-resistant service.
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Power: FGD scrubber linings and condenser tube plates.
How to Order Alloy 20 Sheets & Plates from Nicorex Alloys
Provide the following details to order:
- Material grade: Alloy 20 / UNS N08020 / ASTM B463
- Product form: Sheet, Plate, Coil, Strip, Circle, etc.
- Thickness: (mm or inches)
- Width × Length: (mm) or custom cut-to-size requirements
- Quantity: (in pieces, kg, or metric tons)
- Surface finish: HR, CR, 2B, BA, Mirror, etc.
- Test certification required: EN 10204 3.1 MTC, third-party inspection (TPI) or NACE MR0175 compliance
- Delivery location & timeline:
Contact Nicorex Alloys for competitive pricing, ready-stock availability and fast dispatch from our Mumbai warehouse.
Frequently Asked Questions
What is the price per kg of Alloy 20 sheets and plates in India?
₹700–1,700/kg, varying with thickness, finish, and nickel LME rates. Contact Nicorex Alloys for a live quotation.
What ASTM Specification covers Alloy 20 Sheets and Plates?
ASTM B463 (ASME SB463) covers UNS N08020 plate, sheet and strip in the stabilised-annealed condition.
Can Alloy 20 Plates be used in ASME-Coded Pressure Vessels?
Yes. Per ASME SB463, approved under BPVC Sections III and VIII with allowable stress values to 538°C (1000°F).
How does Alloy 20 perform in H₂SO₄ above 40%?
Best in 20–40% boiling H₂SO₄. Above 40%, corrosion rates climb. Above 60% at elevated temperature, evaluate Alloy 825 or Hastelloy C-276.
What Welding methods are recommended?
Is Alloy 20 Magnetic?
No. Fully austenitic and non-magnetic. Slight cold-work magnetism is removed by solution annealing.