ASTM B668-23 PDF

Overview

ASTM B668-23 is the standard specification for seamless pipe and tube made from iron-nickel-chromium-molybdenum alloys, specifically UNS N08028 and N08029. Developed by ASTM International, this standard sets forth the requirements for the manufacturing, chemical composition, mechanical properties, testing, and delivery of seamless cold-finished or hot-finished pipe and tube intended for general corrosive service. The specification ensures high performance and reliability for industries that require resistance to various forms of corrosion.

Key Topics

• Material Scope and Designation

  • Covers UNS N08028 and N08029 seamless pipe and tube.
  • Applies to both cold-finished and hot-finished manufacturing methods.
  • Intended for general corrosive service where enhanced resistance is required.

• Condition and Heat Treatment

  • Material must be furnished in a solution-annealed condition, followed by rapid cooling.
  • Proper heat treatment is critical for ensuring desired corrosion resistance and mechanical properties.

• Chemical and Mechanical Requirements

  • Strict limits on elements such as carbon, silicon, manganese, phosphorus, sulfur, chromium, nickel, molybdenum, copper, and iron.
  • Each lot must meet required tensile strength, yield strength, and elongation standards.

• Testing and Certification

  • Chemical analysis, tension test, flaring test, and either a hydrostatic or nondestructive electric test are mandatory for each lot.
  • Mandatory manufacturer’s certification stating that all materials and testing conform to specification requirements.

• Ordering and Documentation

  • Clear requirements on what information purchasers need to provide, such as alloy type, dimensions, quantity, and any desired certifications or inspections.

Applications

ASTM B668-23 seamless iron-nickel-chromium-molybdenum alloy pipes and tubes are widely used in situations demanding superior corrosion resistance and mechanical durability. Common applications include:

• Chemical Processing Industries: Ideal for transporting corrosive fluids, acids, and chemical compounds.
• Oil & Gas Sector: Used in piping systems exposed to sour service and harsh environments.
• Marine Engineering: Suitable for use in seawater applications, providing protection against chloride-induced corrosion.
• Power Generation: Applied in heat exchangers, condensers, and components operating under high-temperature and corrosive conditions.
• Pharmaceutical and Petrochemical Facilities: Ensures cleanliness and integrity in high-purity systems.

Related Standards

To ensure comprehensive compliance and performance, ASTM B668-23 references and aligns with several related standards:

• ASTM B829 - General Requirements for Nickel and Nickel Alloys Seamless Pipe and Tube.
• ASTM B899 - Terminology Relating to Non-ferrous Metals and Alloys.

Other standards of interest may include those covering welding, fitting, and fabrication of nickel and alloy piping systems, as well as specific industry standards for corrosive service applications.

Keywords: ASTM B668-23, seamless pipe, seamless tube, iron-nickel-chromium-molybdenum alloy, UNS N08028, UNS N08029, corrosion resistance, chemical processing pipes, ASTM standards, alloy piping specification