Alloy 20 ASTM B464 welded pipes

Alloy 20 (UNS N08020), also known as Carpenter 20, is a nickel-iron-chromium austenitic alloy specifically designed to resist sulfuric acid corrosion. Its welded pipes, manufactured in accordance with ASTM B464, are widely used in chemical and industrial applications requiring exceptional resistance to corrosive environments.

Key Features of Alloy 20 Welded Pipes

- Corrosion Resistance:

Outstanding resistance to sulfuric acid at concentrations up to 20% and higher at moderate temperatures.

Excellent performance in environments containing phosphoric acid, nitric acid, and chlorides.

Good resistance to pitting and crevice corrosion due to its balanced composition.

- Material Composition:

Nickel (32-38%): Provides overall corrosion resistance and maintains ductility.

Chromium (19-21%): Enhances oxidation and pitting resistance.

Molybdenum (2-3%): Adds strength and improves resistance to crevice corrosion.

Copper (3-4%): Helps resist sulfuric acid attack.

- Mechanical Properties:

High tensile strength and excellent toughness.

Superior resistance to stress-corrosion cracking.

- Manufacturing Process:

Produced via welding techniques such as TIG, MIG, or plasma arc welding.

ASTM B464 standard ensures proper mechanical properties, dimensions, and surface finish.

- Dimensional Range:

Available in sizes ranging from 1/2” to 8” nominal diameter, with custom lengths and thicknesses as per project requirements.

- Applications:

Chemical processing industries for handling acids, solvents, and chlorides.

Pharmaceutical and food processing equipment due to its ability to prevent contamination.

Petrochemical plants, particularly in heat exchangers and storage tanks.

- Advantages Over Standard Stainless Steels:

Greater resistance to sulfuric acid compared to 304 and 316 stainless steels.

Better weldability and ductility than most high-performance alloys.

Standards and Certifications

Compliant with ASTM B464 for welded pipes.

Can be manufactured to additional certifications (e.g., ASME SB-464) for use in pressure systems.

Surface Treatment and Finishing

Pipes can be supplied in various finishes, such as pickled, annealed, or polished, based on specific requirements.