What is the composition of ASTM A671?
Standard Source: ASTM A671 is a standard developed by the American Society for Testing and Materials (ASTM), officially titled "Electrofusion Welded Steel Pipes for Atmospheric and Cryogenic Pressures".
Manufacturing Process: Employs electrofusion welding (EFW) technology, which uses the heat generated by an electric current to melt and fuse the edges of the steel plate, forming a continuous and robust weld.
Core Characteristics: Specifically designed for cryogenic environments, exhibiting excellent low-temperature toughness and resistance to brittle fracture.
composition of ASTM A671
A671 Pipe Specification
Product Name: EFW PIPE ASTM A671 pipe
Outer Diameter: 406mm-1422mm
Wall Thickness: 8mm-30mm
Length: 12m, 14m,16m, 26m, 30m
Standard: ASTM A671/671M
Material: A671 CA55, A671 CB60,A671 CB65,A671 CB70, A671 CC60, A671 CC65, A671 CC70, A671 CD70, A671 CD80
Application: Atmospheric and Lower Temperatures
A333 V.S. A671
| Comparison Dimension | A671 Steel Pipes | A333 Steel Pipes |
|---|---|---|
| Standard Definition | ASTM A671: Electric-fusion-welded (EFW) steel pipes for atmospheric and lower temperatures, designed for low-temperature environments, emphasizing weld quality and low-temperature toughness. | ASTM A333: Seamless and welded steel pipes for low-temperature service, covering both seamless and welding processes, applicable to a wider range of low temperatures. |
| Manufacturing Process | Electric-fusion welding (EFW): Weld seams formed by melting steel plate edges with electric current; mandatory heat treatment (e.g., normalizing, tempering) to optimize low-temperature toughness; 100% non-destructive weld testing. | Seamless or welded: Seamless pipes produced via hot rolling/cold drawing; welded pipes use submerged arc welding (SAW) and other processes; some grades require heat treatment but no mandatory full inspection. |
| Low-Temperature Performance Grading | Graded by low-temperature toughness (e.g., CL13, CL22, CL26); CL22 has a minimum service temperature of -45°C with Charpy impact energy ≥27J; CL26 can reach -100°C (extended to -196°C in some scenarios). | Finer grading (e.g., Gr.1, Gr.3, Gr.6); Gr.6 has a minimum service temperature of -50°C (impact energy ≥18J); Gr.3 withstands -150°C; Gr.1 suitable for below -45°C to -253°C (liquid helium environment). |
| Strength-Toughness Balance | Focuses on low-temperature toughness + high-pressure load-bearing; CL26 grade has a yield strength ≥415MPa, suitable for high-pressure, low-temperature main pipelines. | Emphasizes low-temperature toughness first; slightly lower strength (e.g., Gr.6 yield strength ≥240MPa); more suitable for ultra-low-temperature seamless scenarios. |
| Weld Quality Requirements | 100% non-destructive testing (radiographic/ultrasonic) to ensure zero weld defects; adapts to high-pressure, large-diameter pipelines (e.g., LNG main pipeline φ508mm). | Weld testing depends on grade; some require only spot checks; more suitable for small-diameter or less weld-critical scenarios. |
| Typical Application Scenarios | LNG transmission main pipelines, Arctic oil and gas extraction, industrial gas storage and transportation (liquid nitrogen, liquid oxygen), chemical reactor connections. | Ultra-low-temperature seamless pipelines (e.g., liquid oxygen/argon transmission), small-scale LNG plants, low-temperature experimental equipment, aerospace cryogenic systems. |
| Cost and Selection Advice | Higher cost (due to full inspection and heat treatment); suitable for high-pressure, large-diameter, low-temperature main pipelines (e.g., LNG terminal main lines). | Relatively lower cost; suitable for ultra-low-temperature seamless needs or small-diameter pipelines (e.g., laboratory liquid nitrogen pipes, small tank connections). |
