Alloy 28 Pipes & Tubes (UNS N08028) Manufacturer & Supplier - USA Piping Solutions

Some industrial processes present chemical challenges that simply overwhelm standard stainless steel grades. Handling sulfuric acid, for instance, often demands a material specifically built for the task. That material is frequently Alloy 20 Pipes & Tubes. Known throughout industry by its designations UNS N08020 and Carpenter 20®, this specialized nickel-iron-chromium alloy delivers exceptional performance where others corrode. As a prominent manufacturer and highly experienced supplier, USA Piping Solution understands the critical need for reliability in chemical processing, pharmaceutical manufacturing, and similar demanding sectors. We provide top-tier Alloy 20 tubulars, encompassing both seamless (ASTM B729 Pipes) and robust welded constructions, backed by in-depth technical knowledge and efficient global logistics. When your application calls for superior acid resistance, turn to USA Piping Solution for Alloy 20 solutions.

What Makes Alloy 20 (UNS N08020) Stand Out?

Alloy 20 occupies a fascinating middle ground in the world of corrosion-resistant metals. While it shares the austenitic structure of common stainless steels, its substantial nickel content (typically around 35%) elevates its performance considerably, pushing it towards the capabilities of higher nickel alloys, especially concerning certain corrosive threats. Its very conception was driven by the need for a workable alloy that could reliably withstand sulfuric acid, a notoriously difficult chemical to handle across various concentrations and temperatures.

But Alloy 20's utility extends far beyond just sulfuric acid. What are its key strengths?

• Sulfuric Acid Champion: Its resistance to sulfuric acid remains a primary reason for its selection. The alloy's formulation, particularly the synergy between copper and molybdenum, provides excellent serviceability in many sulfuric acid applications where standard stainless would quickly fail.
• Defense Against Chloride SCC: Stress corrosion cracking induced by chlorides is a significant concern for standard austenitic stainless steels. Alloy 20's high nickel content provides vastly superior resistance to this insidious failure mechanism, making it much more reliable in processing environments where chlorides are present, even at elevated temperatures.
• Broad Corrosion Resistance: Beyond sulfuric acid, it performs well against phosphoric acid, nitric acid, and numerous other organic and inorganic chemicals. The molybdenum content also gives it strong defenses against localized attacks like pitting and crevice corrosion.
• Built-in Stabilization: The inclusion of niobium (also called columbium) is crucial. During welding, niobium preferentially combines with carbon, preventing the formation of chromium carbides along the grain boundaries. This stabilization step is vital because it ensures the material maintains its resistance to intergranular corrosion, even after being heated during welding, eliminating the need for post-weld heat treatments in most scenarios.
• Good Fabricability: Despite its complex chemistry, Alloy 20 retains the characteristic good ductility of austenitic alloys. This means it can be formed, bent, and welded using established procedures (though techniques suitable for nickel alloys are advised).

This powerful combination of properties makes Alloy 20 Pipes & Tubes a vital tool for engineers designing systems to safely contain and transport some of the industry's most challenging process fluids.

Alloy 20 Piping: Adhering to Technical Specifications

Reliable performance demands that materials meet clearly defined technical standards. USA Piping Solution ensures that all Alloy 20 Pipes & Tubes adhere to the rigorous requirements of established international specifications.

Key Standards and Designations

Category	Identifiers and Governing Documents
UNS Designation	N08020
Common Trade Names	Alloy 20, Carpenter 20®, Incoloy® Alloy 20
Werkstoff Nr.	2.4660 (European Material Number)
Primary ASTM/ASME	B729 / SB729: The main specification for Seamless Pipe and Tube.
Specifications	B464 / SB464: Key standard governing Welded Pipe. B468 / SB468: Covers requirements for Welded Tube.
Note: Related standards like B366 (Fittings) & B473 (Bar) apply to associated components.

Dimensional Capabilities

Dimension	Typical Production Range
Outer Diameter (OD)	From small-bore instrumentation tubing (~0.125" / 6mm) up to large process piping diameters (e.g., 24" / 610mm).
Wall Thickness (WT)	Spanning light-gauge options (~0.5mm) through heavy-wall pipe schedules (Sch 80, 160, walls up to ~20mm).
Length	Standard random lengths (SRL/DRL) or precision cut-to-length as required.
Tolerances	Dimensional controls (OD, WT, etc.) follow the strict guidelines within the specified ASTM/ASME standard (B729, B464, etc.).

Our capabilities cover a wide range of sizes. Let us know your specific dimensional needs.

The Chemical Recipe: Alloy 20's Formula for Resilience

The exceptional ability of Alloy 20 to withstand aggressive chemicals is no accident; it’s the direct result of a sophisticated and carefully balanced chemical composition:

Element	Symbol	Typical Content (% by Weight)	What It Brings to the Table
Nickel	Ni	32.0 – 38.0%	The high nickel foundation provides excellent resistance to chloride stress corrosion cracking, maintains the stable austenitic structure, and contributes to overall corrosion resistance.
Chromium	Cr	19.0 – 21.0%	Essential for forming the protective passive oxide layer, crucial for resisting oxidizing conditions and contributing to pitting defense.
Iron	Fe	Balance (~31% - 44%)	Makes up a significant portion of the alloy's structure.
Copper	Cu	3.0 – 4.0%	Works particularly well with molybdenum to grant superior performance against sulfuric acid.
Molybdenum	Mo	2.0 – 3.0%	A key player in resisting reducing acids (like sulfuric) and significantly boosts resistance to pitting and crevice corrosion, especially where chlorides are present.
Niobium (Nb)	Nb (+Ta)	≥ 8x%C, ≤ 1.0%	This is the stabilizing agent. It effectively locks up carbon during welding, preventing chromium depletion and maintaining resistance to intergranular corrosion in the heat-affected zone.
Carbon	C	≤ 0.07%	Its potential negative impact at high temperatures is managed by the niobium stabilization.
Manganese	Mn	≤ 2.0%	Adds to strength and helps during the steelmaking process.
Silicon	Si	≤ 1.0%	Primarily used for deoxidation during melting.
Phosphorus	P	≤ 0.045%	Impurity, levels kept low.
Sulfur	S	≤ 0.035%	Impurity, minimized for better weld quality.

This intricate blend equips UNS N08020 Pipes with a unique skill set for handling particularly challenging corrosive media.

Mechanical Strength Meets Fabricability

While renowned for corrosion resistance, Alloy 20 doesn't sacrifice mechanical integrity. It offers solid properties suitable for constructing durable equipment, combined with the workable nature expected of an austenitic alloy. Here’s a look at typical minimums for annealed material:

Property	Representative Minimum Figure	What This Means for Design and Fabrication
Tensile Strength (UTS)	≥ 550 MPa (≥ 80 ksi)	Good overall strength, capable of handling significant pressure and mechanical stresses.
Yield Strength (0.2% offset)	≥ 241 MPa (≥ 35 ksi)	Provides reliable resistance against permanent deformation under typical operating loads.
Elongation (% in 50mm/2")	≥ 30%	Excellent ductility is indicated by this high value, allowing for significant forming, bending, and expansion operations during fabrication.
Hardness (Rockwell B)	Typically ≤ 90 HRB (Max)	Suggests reasonable machinability in the annealed state, although managing work hardening is important during machining operations.
Density	Approx. 8.1 g/cm³	Standard density for this class of nickel-iron-chromium alloy.
Melting Range	Around 1350–1370°C (2460–2500°F)	Defines the transition from solid to liquid, relevant for high-temp considerations.

This profile confirms that Alloy 20 Seamless Tubes and their welded counterparts provide both the necessary chemical resistance and the mechanical robustness required for demanding service, along with the fabricability needed to build complex equipment.

Available Forms and Surface Finishes

To accommodate diverse construction methods and final use requirements, USA Piping Solution offers Alloy 20 tubulars in various configurations:

• How It's Made:
  • Seamless: Produced without any weld seam (often per ASTM B729 Pipes), this method offers maximum material uniformity and is frequently specified for high-pressure or highly critical services.
  • Welded: Formed from plate or strip and joined with a high-integrity weld (ERW, EFW, TIG processes, following standards like ASTM B464/B468). This provides a practical and often more economical route, especially suitable for larger pipe diameters.
• Shapes Available:
  • Round: The standard format for most piping and tubing needs.
  • Square & Rectangular: Available for structural components, custom tank fabrication, or specialized equipment designs.
  • Coiled: Long, continuous lengths can be supplied for specific uses like chemical injection or control systems.
• Surface Conditions:
  • Annealed & Pickled (A&P): The most common finish, offering optimal corrosion resistance and a clean, matte surface post-heat treatment.
  • Bright Annealed (BA): Provides a smoother, brighter look via controlled atmosphere annealing, sometimes preferred visually or for specific process interfaces.
  • Polished: Mechanical polishing to achieve various levels of surface smoothness (specified by grit number) is available for applications demanding it.

Where Alloy 20 Makes a Critical Difference: Applications

Alloy 20's specific resistance profile carves out essential roles in industries grappling with particularly aggressive substances:

• Chemical Processing: Indispensable for handling sulfuric acid, phosphoric acid, nitric acid mixtures, and other harsh chemicals. Used in reactors, piping systems, heat exchanger bundles, storage tanks, pumps, and valves.
• Pharmaceuticals: Equipment requiring resistance to aggressive cleaning protocols or chemical processes.
• Food & Beverage: Used in acidic product processing and equipment cleaned with strong sanitizing agents.
• Heat Transfer Equipment: DIN 2.4660 Tubes perform reliably in corrosive heat exchanger applications.
• Petrochemicals: Suitable for refining units handling acidic catalysts or byproducts.
• Synthetic Fiber Manufacturing: Utilized in sulfuric acid-driven processes.
• Metal Treatment: Applied in acid pickling lines and heating equipment.
• Explosives Production: For managing corrosive acidic environments safely.

Quality Assurance: Certifications & Compliance

For materials destined for critical service, documented proof of quality isn't just helpful, it's essential. USA Piping Solution guarantees that all Alloy 20 Pipes & Tubes are backed by thorough certification and meet relevant industry standards:

• ISO 9001:2015 Framework: Our ISO-certified system ensures consistency from sourcing to delivery.
• Material Test Reports (EN 10204 3.1 / 3.2): Provided standard, offering full traceability and verified test results. 3.2 reports available on request.
• NACE MR0175 / ISO 15156 Ready: Suitable for sour service when requested with supporting documentation.
• PED Certification Capability: Compliant with the European Pressure Equipment Directive when required.
• ASTM/ASME Standards Conformance: All materials meet the relevant ASTM/ASME specs (e.g., B729, B464, B468).
• Third-Party Inspection (TPI) Services: Coordinated upon request for added verification.

Why USA Piping Solution for Your Alloy 20 Needs?

Choosing the right supplier for specialized materials like Alloy 20 involves more than just price. USA Piping Solution offers significant advantages:

• Targeted Inventory: Stocking seamless and welded Alloy 20 in high-demand sizes.
• In-Depth Alloy Expertise: Technical guidance on Alloy 20’s use, fabrication, and performance.
• Custom Processing Solutions: Cutting, finishing, and other value-added services tailored to your needs.
• Strong Mill Relationships: Access to reliable, competitively priced material from global mills.
• Reliable Global Logistics: Efficient domestic and international deliveries with complete documentation.
• Unwavering Commitment to Quality: Backed by documentation, TPI support, and ISO-certified processes.

Exploring Alternative High-Performance Alloys

Depending on the specific corrosive challenge, other advanced materials might also be considered. USA Piping Solution also supplies

Final Call to Action

Are your operations battling aggressive acids or chloride-rich environments that demand more than standard stainless steel can offer? Alloy 28 Pipes & Tubes (UNS N08028) from USA Piping Solution provide the robust, reliable defense you need. We supply premium Carpenter 28 Tubes and pipes, including seamless forms meeting ASTM B729, designed specifically for long-term performance in demanding chemical, pharmaceutical, and industrial applications. Invest in the durability required to protect your critical processes.

Reach out to USA Piping Solution for Alloy 28 and experience:
✅ Access to a specialized inventory focusing on key sizes.
✅ Custom cutting and processing options to fit your project.
✅ Dependable global shipping supported by full certifications.
✅ Expert technical advice from seasoned alloy professionals.

📞 Ready to specify a proven solution for tough corrosive challenges? Contact us today for a competitive quote! Discuss your DIN 2.4660 Tubes or pipe needs with our experts and let USA Piping Solution deliver the high-performance materials essential for your success.

Request Your Alloy 28 Quote