ASTM A672 Grade C60/C65/C70 EFW Pipes description
ASTM A672 C60/C65/C70 electrofusion welded pipe is a medium- and high-temperature pressure-bearing carbon manganese steel welded pipe conforming to the ASTM A672 standard. Its core characteristics are:
Process Characteristics
Electrofusion Welding (EFW): Metallurgical bonding is achieved by melting the edges of the steel strip with an electric arc, resulting in a smooth inner wall (roughness Ra≤3.2μm) and reduced fluid resistance.
Normalizing: Forced heating to 900-930℃ followed by air cooling refines the grain structure and improves high-temperature performance.
Grade C60 V.S Grade C65 V.S. Grade C70
| Parameter | C60 | C65 | C70 |
|---|---|---|---|
| Yield Strength | ≥415 MPa (60 ksi) | ≥450 MPa (65 ksi) | ≥485 MPa (70 ksi) |
| Tensile Strength | ≥515 MPa | ≥535 MPa | ≥620 MPa |
| Maximum Service Temperature | 400℃ | 450℃ | 480℃ |
| Key Composition | C≤0.22%, Mn:1.00-1.60% | C≤0.22%, Mn:1.15-1.60% | C≤0.22%, Mn:1.15-1.60% |
| Processing Requirements | Normalizing treatment + EFW welding | Normalizing treatment + EFW welding | Normalizing treatment + EFW welding |
| Cost Efficiency | Lowest cost | Balanced cost-performance | Highest cost (15% strength premium) |
Applications
C60 (Economic Medium Pressure)
Petrochemical Industry: Hot oil pipeline for atmospheric and vacuum distillation units (≤10 MPa/380℃)
Power System: Steam header for geothermal power plants (≤8 MPa/350℃)
Industrial Pipeline: Heat transfer oil circulation system (≤8.7 MPa/390℃)
C65 (Balanced Medium-High Pressure)
Refinery: Catalytic cracking slurry pipeline (12 MPa/420℃)
LNG Plant: Regenerated gas transmission pipeline (10 MPa/-50~200℃)
Chemical Plant: Inlet and outlet pipes for methanol synthesis reactor (15 MPa/400℃)
C70 (High Pressure, High Temperature)
Coal/Nuclear Power Plant: Main steam pipeline (≥18 MPa/480℃)
Hydrogenation Unit: Reaction product pipeline (15 MPa/380℃ + H₂ environment)
Ethylene Plant: Cracking gas quench pipeline (12 MPa/380℃ + H₂ environment) MPa/450℃)
Test and inspection
Packaging and shipping
