Alloy 20 UNS N08020 Overview
Alloy 20 (UNS N08020 / W.Nr. 2.4660) is an austenitic nickel-iron-chromium alloy containing copper and molybdenum, with stabilization requirements defined by the applicable material specification. It was developed for corrosion resistance in sulfuric-acid processing and is also selected for chemical, pharmaceutical and food-processing equipment when the service environment has been reviewed.
| Item |
Details |
| Grade |
Alloy 20 / UNS N08020 / W.Nr. 2.4660 |
| Alloy family |
Nickel-iron-chromium-molybdenum-copper corrosion-resistant alloy |
| Supply scope |
Plate, sheet, strip, bar, rod, wire, forgings, seamless pipe/tube and welded tube |
| Order basis |
Product form, applicable specification, dimensions, heat treatment, inspection and certification |
Available Alloy 20 Product Forms
| Item |
Details |
| Plate, sheet and strip |
Thickness, width, length, surface and flatness confirmed against the purchase specification |
| Bar, rod and wire |
Diameter, tolerance, length or coil configuration, surface and condition confirmed |
| Forgings |
Drawing, dimensions, machining allowance, heat treatment and inspection scope required |
| Pipe and tube |
Seamless or welded construction, OD, wall thickness, length, end preparation and test requirements |
| Custom processing |
Cutting, machining and other services reviewed against drawing and final inspection requirements |
Sheet / Plate
|
Bar / Rod
|
Pipe / Tube
|
Applicable Product Standards
| Product Form |
Specification Guidance |
| Bar and wire |
ASTM B473 / ASME SB-473, subject to the ordered edition and product requirements |
| Forgings and flanges |
ASTM B462 / ASME SB-462 when applicable to the ordered component |
| Seamless pipe and tube |
ASTM B729 / ASME SB-729 where specified |
| Welded tube |
ASTM B468 / ASME SB-468 where specified |
| Plate, sheet and strip |
ASTM B463 was historically used for UNS N08020 plate, sheet and strip and has been withdrawn; the purchaser must state the accepted project or replacement specification |
| Important |
Standard edition, dimensional standard, supplementary requirements and acceptance criteria must be confirmed before quotation |
Typical Chemical Composition
| Element |
Typical Range / Requirement |
| Nickel (Ni) |
32.0-38.0% |
| Chromium (Cr) |
19.0-21.0% |
| Molybdenum (Mo) |
2.0-3.0% |
| Copper (Cu) |
3.0-4.0% |
| Iron (Fe) |
Balance |
| Carbon (C) |
0.07% max; some purchase specifications or product data may apply tighter limits |
| Manganese / Silicon |
2.00% max / 1.00% max |
| Stabilizing elements |
Niobium plus tantalum requirements must be checked against the ordered material specification and certificate |
Corrosion Resistance and Material Selection
| Item |
Details |
| Sulfuric-acid service |
Alloy 20 is widely considered for sulfuric-acid equipment, but concentration, temperature, contamination and flow conditions must be reviewed |
| Chloride environments |
Nickel content helps reduce susceptibility to chloride stress-corrosion cracking compared with conventional austenitic stainless steels |
| Localized corrosion |
Chromium and molybdenum support resistance to oxidizing and localized attack; actual performance depends on the complete environment |
| Fabrication |
Good formability and weldability are possible with appropriate procedures and control of heat treatment |
| Selection warning |
This page is not a corrosion guarantee. Provide process chemistry, temperature and design conditions for engineering review |
Dimensions, Condition and Processing
| Item |
Details |
| Dimensions |
Provide diameter or thickness x width x length, tolerances and drawing where applicable |
| Condition |
Solution-annealed, stabilized-annealed, annealed or other condition as required by the applicable product specification |
| Surface |
Hot-finished, cold-finished, pickled, bright, polished, machined or project-specified finish |
| Processing |
Cutting, straightening, machining, drilling, forming and preparation subject to product form and drawing |
| Mechanical properties |
Acceptance values depend on product form, dimensions, condition and governing specification; they are verified against the final purchase order rather than applied as one universal value |
Discuss Alloy 20 Form, Standard and Corrosion Service
Typical Applications
| Item |
Details |
| Chemical processing |
Acid-handling equipment, process piping, tanks, heat-exchanger components and pickling systems |
| Pharmaceutical equipment |
Process components requiring corrosion resistance and controlled documentation |
| Food processing |
Equipment exposed to acidic media or aggressive cleaning environments, subject to hygiene and design requirements |
| Petrochemical and industrial service |
Pumps, valves, shafts, fasteners and fabricated components for reviewed process environments |
| Fabricated equipment |
Vessels, agitators, coils and internals manufactured from the appropriate Alloy 20 product form |
Quality Inspection and Documentation
| Item |
Details |
| Material identity |
Heat or lot traceability maintained through processing and packing |
| Chemical analysis |
Verified against the ordered grade and applicable specification |
| Dimensions and workmanship |
Inspection based on the product form, drawing, tolerances and surface requirements |
| Mechanical testing |
Performed where required by the governing product specification and order |
| Optional inspection |
PMI, ultrasonic, penetrant, corrosion or third-party inspection can be arranged when technically applicable and stated before quotation |
| Documentation |
EN 10204 3.1 certificate or other agreed documentation supplied according to the purchase order |
Packaging and Export Delivery
| Item |
Details |
| Plate and sheet |
Protected surfaces, edge guards, moisture barrier and reinforced pallets or cases as required |
| Bar and rod |
Bundled or boxed with separation and protection selected according to diameter and finish |
| Wire |
Coils or spools protected from deformation, moisture and contamination |
| Pipe, tube and forgings |
Ends and machined surfaces protected; lifting and case design matched to dimensions and weight |
| Identification |
Grade, heat or lot number, dimensions, net weight and order reference marked on the package |
Typical SASA ALLOY export packaging; the final method is confirmed for the ordered product form and shipping route.
RFQ Confirmation Checklist
| Please Provide |
Required Detail |
| Product form |
Plate, sheet, strip, bar, wire, forging, pipe or tube |
| Material specification |
ASTM/ASME or project specification and required edition |
| Dimensions |
Size, tolerances, length, drawing and quantity |
| Condition and surface |
Heat treatment, finish, edge/end preparation and processing |
| Service conditions |
Process medium, concentration, temperature, pressure and design requirements |
| Testing and documents |
Certificate type, inspection plan, supplementary testing and third-party requirements |
| Delivery |
Packing, marking, destination and requested date |
Request an Alloy 20 UNS N08020 Quote
All technical values, standards and service suitability are confirmed against the final purchase specification before order acceptance.
Previous: Inconel 690 bar
Next: Inconel 625 Pipe Tube
