Alloy 20 (Carpenter 20 / UNS N08020) Process Pipes
Austenitic nickel-iron-chromium-copper alloy stabilized with niobium for extreme resistance to sulfuric, nitric, and phosphoric acids.
ASTM B729 / ASME SB729 UNS N08020 (Alloy 20) Pipe
Starlight Tubes is a specialized manufacturer of Alloy 20 (UNS N08020 / Carpenter 20 / DIN 2.4660) seamless and welded pipes. Specifically developed for sulfuric acid applications, Alloy 20 offers remarkable resistance to general corrosion, pitting, and crevice corrosion in chemicals containing chlorides, nitric acid, and phosphoric acid.
Our Alloy 20 pipes are supplied in stabilized annealed condition with full metallurgical certification, PMI inspection, and hydrostatic pressure testing. Widely utilized in sulfuric acid pickling tanks, synthetic rubber manufacturing, plastics synthesis, and pharmaceutical processing.
Technical Specifications
ASTM / ASME CompliantTechnical Specifications — Alloy 20 (UNS N08020)
Certified chemical limits and mechanical tensile properties for ASTM B729 Alloy 20
| Grade | Ni | Cr | Mo | Cu | Nb | C (max) | Fe |
|---|---|---|---|---|---|---|---|
| Alloy 20 | 32.0-38.0 | 19.0-21.0 | 2.0-3.0 | 3.0-4.0 | 8xC min - 1.0 | 0.07 | Balance (30% min) |
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Direct Mill Supply for Alloy 20 Pipes
Starlight Tubes provides top-grade Alloy 20 pipes with certified chemical testing, Niobium stabilization verification, and worldwide export shipping.
Frequently Asked Questions on Alloy 20 (Carpenter 20) Pipes
Key engineering, tolerance, and international compliance answers from our metallurgical quality desk.
The precise addition of 3.5% copper combined with 35% nickel provides superior passivation in sulfuric acid, enabling long-term equipment life in boiling sulfuric acid up to 40% concentration.
Request Project Quotation for Alloy 20 (Carpenter 20) Pipes
Submit your required sizes, wall thicknesses, material grades, and total tonnage. Our technical sales engineers respond with complete mill pricing and lead times within 24 hours.