Alloy 20 / 020，Incoloy 020 Fittings，

British Specs:，American Specs:，German Specs: WS 2.4660

Alloy 20 / 020 (Incoloy 020 Wire) - Introduction with Composition, Properties, Applications and Product Forms

Alloy 20, also known as Alloy 020 or commercially as Incoloy 020, is a nickel-iron-chromium-molybdenum alloy specifically engineered for exceptional resistance to sulfuric acid and a wide range of corrosive environments, including both oxidizing and reducing conditions. This high-performance alloy combines superior corrosion resistance with good mechanical strength, excellent weldability, and versatility, making it a staple in chemical processing and industrial applications involving aggressive chemicals. It is available in a comprehensive range of forms to meet diverse industrial needs, including Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Incoloy 020 Wire, in particular, is valued for its flexibility, precision, and corrosion resistance, making it ideal for intricate components in chemical processing, pharmaceuticals, and pollution control industries. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The precisely balanced chemical composition of Alloy 20 / 020 (Incoloy 020) is the foundation of its exceptional corrosion resistance and mechanical performance. The typical composition (by weight) is as follows:

Nickel (Ni): 32-38% (primary matrix element, providing corrosion resistance and structural stability, particularly in sulfuric acid environments)

Iron (Fe): 31-44% (enhances mechanical strength and fabricability)

Chromium (Cr): 19-21% (critical for oxidation resistance, forming a protective chromium oxide layer in oxidizing environments)

Molybdenum (Mo): 2.0-3.0% (boosts resistance to pitting, crevice corrosion, and reducing acids such as sulfuric acid)

Copper (Cu): 3.0-4.0% (a key element for improving resistance to sulfuric acid and other reducing acids)

Carbon (C): ≤ 0.07% (controlled to minimize carbide precipitation, preserving corrosion resistance, especially after welding)

Manganese (Mn): ≤ 2.0% (aids in deoxidation during manufacturing and improves weldability)

Silicon (Si): ≤ 1.0% (assists in forming a stable oxide layer, enhancing oxidation resistance)

Niobium + Tantalum (Nb + Ta): 0.8-1.2% (stabilizes the alloy against carbide precipitation, preventing intergranular corrosion)

Sulfur (S): ≤ 0.03% (kept at low levels to ensure good ductility and weldability)

Phosphorus (P): ≤ 0.04% (controlled to maintain corrosion resistance and avoid embrittlement)

This carefully engineered composition, with its balanced blend of nickel, chromium, molybdenum, and copper, delivers the alloy's signature resistance to sulfuric acid, pitting corrosion, and general chemical attack, making it suitable for the most demanding corrosive industrial environments.

Key Properties

Alloy 20 / 020 (Incoloy 020 Wire) and its various forms exhibit a robust set of properties that make them indispensable in corrosive, high-temperature, and high-stress applications:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 550-690 MPa (79,800-100,100 psi)

Yield strength (0.2% offset): 240-310 MPa (34,800-44,900 psi)

Elongation (in 50 mm): 30-40% (excellent ductility, enabling complex forming, bending, and welding across all product forms)

Hardness: 150-190 HB (Brinell hardness, indicating good machinability and workability)

High-Temperature Performance:

Thermal stability: Maintains significant strength up to 600°C (1112°F), with tensile strength remaining above 280 MPa at 400°C (752°F)

Creep resistance: Exhibits good creep resistance at 300-500°C (572-932°F), suitable for long-term service under sustained stress in moderate high-temperature systems

Oxidation resistance: Resistant to oxidation in air and combustion gases up to 800°C (1472°F), forming a dense, self-healing chromium oxide layer

Thermal fatigue resistance: Good resistance to thermal cycling, making it suitable for applications with moderate temperature fluctuations

Corrosion Resistance:

Sulfuric acid resistance: Exceptional resistance to sulfuric acid across a wide range of concentrations (from dilute to concentrated) and temperatures, a defining feature of the alloy

General corrosion resistance: Excellent resistance to both oxidizing and reducing acids, including hydrochloric acid (dilute), phosphoric acid, and organic acids

Chloride resistance: Superior resistance to pitting and crevice corrosion in chloride-rich environments, including seawater, brines, and industrial effluents

Wet corrosion: Resistant to alkaline solutions, industrial chemicals, and polluted water, ensuring versatility across diverse industries

Stress corrosion cracking (SCC): Highly resistant to SCC in sulfuric acid and chloride-containing environments, even at elevated temperatures

Intergranular corrosion resistance: Resistant to intergranular corrosion after welding, thanks to niobium/tantalum stabilization, which prevents carbide precipitation at grain boundaries

Physical Properties:

Density: 8.0 g/cm³ (0.289 lb/in³)

Thermal conductivity: 15.0 W/(m·K) at 20°C (68°F), increasing to 21.0 W/(m·K) at 600°C (1112°F)

Melting point: 1350-1400°C (2462-2552°F)

Coefficient of thermal expansion: 16.0 μm/(m·K) (20-100°C), rising to 18.5 μm/(m·K) at 600°C (1112°F)

Modulus of elasticity: 200 GPa (29,000 ksi) at room temperature, decreasing to 165 GPa (23,900 ksi) at 600°C (1112°F)

Product Forms

Alloy 20 / 020 (Incoloy 020) is manufactured in a diverse range of forms to accommodate specialized industrial processes across chemical, pharmaceutical, and pollution control sectors:

Bar: Available as Round bar (diameters from 8 mm to 300 mm) and Flat bar (thickness 6 mm to 150 mm, width 20 mm to 600 mm), ideal for machining into valve components, pump shafts, and chemical processing hardware.

Ribbon: Thin, flat strips (thickness 0.1 mm to 2 mm, width 5 mm to 100 mm) used in electrical contacts, gaskets, and seals for corrosive equipment.

Wire: Incoloy 020 Wire (diameters 0.05 mm to 10 mm) offers excellent flexibility and corrosion resistance, making it suitable for thermocouple leads, sensor wiring, woven mesh filters, and precision springs in aggressive chemical environments.

Rods: Solid cylindrical rods (diameters 3 mm to 50 mm) suitable for structural supports in chemical reactors, pharmaceutical equipment, and pollution control systems.

Tube and Pipe: Seamless and welded options (outer diameter 6 mm to 200 mm, wall thickness 0.5 mm to 20 mm) for transporting corrosive fluids, including sulfuric acid, hydrochloric acid, and industrial chemicals, in processing systems.

Foil: Ultra-thin sheets (thickness 0.01 mm to 0.1 mm) used in lightweight corrosion barriers, liners for precision pharmaceutical instruments, and electrical components.

Plate and Sheet: Flat forms (plate: thickness 5 mm to 100 mm; sheet: 0.3 mm to 5 mm) for fabricating reactor vessel liners, storage tanks, heat exchanger panels, and structural parts in chemical plants.

Strip: Narrow, flat strips (thickness 0.1 mm to 3 mm, width 10 mm to 200 mm) for precision manufacturing in gaskets, clips, and electrical components for corrosive systems.

Forging Stock: Billets and ingots for hot forging into complex shapes such as pump impellers, valve bodies, and pharmaceutical processing hardware.

Applications

The exceptional corrosion resistance properties of Alloy 20 / 020 (Incoloy 020 Wire) across its various forms make it a critical material in industries requiring performance in aggressive chemical environments:

Chemical Processing:

Sulfuric acid production and handling: Tanks, pipes, and valves (from plate, tube, and bar) for processing and transporting sulfuric acid across a wide range of concentrations and temperatures, from dilute to concentrated.

Acid manufacturing: Equipment for producing hydrochloric acid, phosphoric acid, and organic acids, including reaction vessels (from plate) and transfer lines (from tube).

Chemical synthesis: Reactors, agitators, and heat exchangers (from plate, bar, and tube) for producing specialty chemicals, dyes, and industrial intermediates.

Pharmaceuticals and Food Processing:

Pharmaceutical manufacturing: Equipment for producing high-purity drugs and APIs, including reaction vessels (from plate), transfer lines (from tube), and filters (from wire mesh), ensuring product purity and corrosion resistance.

Food processing: Components for handling acidic food products, such as fruit juices and pickling solutions, including tanks (from sheet) and conveyor parts (from bar), meeting strict hygiene standards.

Cosmetics production: Mixing tanks and piping (from plate and tube) for formulations involving acids and preservatives.

Pollution Control:

Flue gas desulfurization (FGD) systems: Components for removing sulfur dioxide from power plant emissions, including scrubber vessels (from plate), spray nozzles (from forging stock), and ducting (from sheet).

Wastewater treatment: Equipment for processing industrial wastewater, including clarifiers (from plate), sludge pumps (from bar), and chemical dosing lines (from tube).

Air pollution control: Filters and scrubbers (from wire mesh and sheet) for removing corrosive pollutants from industrial exhaust gases.

Metallurgical and Mining:

Acid leaching: Equipment for extracting metals from ores using acids, including leach tanks (from plate) and agitators (from bar).

Electroplating: Tanks, racks, and anode/cathode supports (from sheet, wire, and bar) resisting plating bath chemicals, including sulfuric acid-based solutions.

Mining chemicals: Piping and storage tanks (from tube and plate) for handling acids used in mineral processing.

Specialized Applications by Form:

Wire: Thermocouple leads in chemical reactors, sensor wiring in corrosive environments, and woven mesh filters for acid filtration and pharmaceutical processing.

Tube/Pipe: Chemical transport lines, heat exchanger tubes in acid processing, and sampling lines for aggressive fluids in laboratories.

Plate/Sheet: Reactor vessel liners, storage tank walls, and structural panels in chemical plants and pharmaceutical facilities.

Bar/Forging Stock: Machined valves, pump shafts, and agitator blades requiring high strength and corrosion resistance in aggressive environments.

In summary, Alloy 20 / 020 (Incoloy 020 Wire) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional resistance to sulfuric acid and other aggressive chemicals, along with good mechanical strength and formability. Its diverse product forms enable tailored solutions across chemical processing, pharmaceuticals, and pollution control sectors, establishing it as a critical material in the most demanding corrosive industrial applications.

Packing of Standard Packing:

 Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 2685 gallon liquid totes Special package is available on request.