X65 large-diameter welded pipe is a high-strength pipeline steel produced according to API 5L standards. Its minimum yield strength is 450 MPa (65 ksi), and it is produced using a microalloyed controlled rolling and cooling (TMCP) process. Its chemical composition features a low carbon content (typically ≤0.12%) and extremely low levels of harmful elements such as sulfur and phosphorus (≤0.005% and ≤0.020%, respectively), significantly improving the pipe's resistance to hydrogen-induced cracking (HIC) and sulfide stress corrosion cracking (SSCC).
Mechanical Properties
Typical mechanical parameters are: yield strength ≥448MPa, tensile strength ≥535MPa, Charpy impact energy at -20℃ ≥80J, hardness ≤250HV10. Through controlled rolling and cooling technology, the elongation at break can reach over 30%.
Dimensional Accuracy
Outer diameter tolerance ±0.75%, wall thickness tolerance 15%/-10%, ellipticity ≤0.6%D, meeting the PSL2 grade requirements of ISO3183-2:2019.
Environmental Adaptability
Good impact toughness is maintained even at 40°C. Some products have passed DNV-OS-F101 Arctic certification. X65MS steel grade, resistant to H2S corrosion, has been widely used in sulfur-containing gas fields.
Price Range
Basic Specifications (e.g., φ610×10mm): Approximately RMB 5900/ton to RMB 6000/ton (including tax, April 2024 data);
Large Diameter Thick-Walled Pipes (e.g., φ1016×22mm): Price increases of 10% to 15% due to increased rolling difficulty;
Customized Products (e.g., Acid-Resistant X65QS): Additional costs of approximately RMB 500/ton to RMB 800/ton.
Price Drivers:
Raw Material Costs: Price fluctuations of alloys such as chromium and nickel directly impact costs;
Production Process: Hot-rolled pipes are less expensive than cold-drawn pipes, but the latter require higher precision;
Certification Requirements: API 5L PSL2 certification adds testing steps, driving up prices.
API 5L X65 Large Diameter Welded Pipe Factory
