ASTM B535 Alloy 330 Seamless Pipe for High-Temperature Service with Carburization Resistance

ASTM B535 UNS N08330 Seamless Pipe is manufactured from Alloy 330, a nickel-iron-chromium-silicon alloy developed for elevated-temperature and corrosive service. UNS N08330 is commonly selected for equipment exposed to oxidizing, carburizing and thermal-processing environments, where material selection must account for temperature, atmosphere and corrosion conditions. The pipe is supplied in seamless construction and can be manufactured in hot-finished or cold-finished conditions according to the required size and ASTM B535 specifications.

• High-Temperature Service: Alloy 330 is designed for applications involving elevated temperatures and thermal processing. Its nickel-chromium-iron-silicon composition provides resistance to oxidation under suitable high-temperature operating conditions.
• Carburization Resistance: The alloy is used in environments where carburization is a material-selection concern, including certain furnace and thermal-processing applications.
• Austenitic Alloy Structure: UNS N08330 is an austenitic nickel-iron-chromium-silicon alloy selected for its combination of high-temperature capability and resistance to various industrial process environments.
• Seamless Pipe Construction: The seamless manufacturing route provides a continuous pipe structure without a longitudinal weld seam and is available in hot-finished and cold-finished forms.
• Annealed Delivery Condition: ASTM B535 products are supplied in the specified annealed condition, with material testing and inspection performed according to the applicable requirements.

• Heat Treatment Furnaces
• Industrial Furnace Equipment
• Furnace Process Piping
• Petrochemical Process Equipment
• Chemical Processing Units
• Thermal Processing Systems
• Carburizing Atmosphere Equipment
• High-Temperature Process Piping
• Heat Transfer Equipment
• Industrial Heating Systems

1. Furnace & Heat Treatment Equipment: Alloy 330 pipe can be used for selected furnace components and thermal-processing systems where oxidation and carburization resistance are important design considerations.

2. Petrochemical & Chemical Processing: The alloy is suitable for selected process environments involving elevated temperatures and corrosive media.

3. High-Temperature Process Piping: UNS N08330 pipe can be specified for process lines where operating temperature and atmospheric exposure require a nickel-based alloy rather than a conventional stainless steel grade.

Pipe dimensions can be manufactured according to the applicable standard or project specification. Typical dimensional controls include:

• Outside Diameter
• Wall Thickness
• Ovality
• Straightness
• Length
• End Squareness
• Surface Condition

For project-specific requirements, dimensional tolerances can be reviewed against the applicable purchase specification before production.

Available inspection and documentation may include:

• Chemical Composition Analysis
• Tensile Test
• Yield Strength Test
• Elongation Test
• Hardness Test
• Flattening Test
• Hydrostatic Test
• Nondestructive Electric Test
• Dimensional Inspection
• Surface Inspection
• Heat Treatment Records
• Positive Material Identification (PMI)
• EN 10204 3.1 Material Certificate

Material selection for high-temperature equipment depends on operating temperature, process atmosphere, corrosion mechanism and mechanical requirements. Alloy 330 is specifically positioned for applications where oxidation, carburization and thermal exposure are important considerations. Conventional stainless steel grades may be suitable for less demanding environments, depending on the actual operating conditions. For engineering selection, the appropriate grade should be determined from the complete service conditions rather than temperature alone.

• What is UNS N08330? UNS N08330 is a nickel-iron-chromium-silicon alloy commonly known as Alloy 330.
• What is ASTM B535 N08330 Pipe used for? Typical applications include furnace equipment, heat-treatment systems, thermal processing equipment, chemical processing and selected high-temperature process piping.
• Is Alloy 330 a stainless steel? Alloy 330 is more accurately classified as a nickel-iron-chromium-silicon alloy, rather than a conventional stainless steel grade.
• Is N08330 available as seamless pipe? Yes. ASTM B535 covers seamless pipe and tube in UNS N08330 and related grades, subject to the applicable product requirements.