What is the API 5L X80 equivalent?
API 5L X80, as a high-strength pipeline steel in the American Petroleum Institute (API) standard, has global equivalents that cover the following systems:
1. Chinese National Standard (GB)
Standard Name: GB/T 9711-2019 Steel Pipes for Pipeline Transmission Systems in the Oil and Gas Industry
Equivalent grade: L555 (PSL1/PSL2)
Chemical composition counterpart:
Carbon (C) ≤ 0.18%, manganese (Mn) ≤ 1.90%, silicon (Si) ≤ 0.45%, sulfur (S), phosphorus (P) content is strictly controlled at ≤ 0.015%.
Add trace alloying elements (such as niobium, vanadium) to optimise the stability of the organisation, consistent with the composition of X80.
Mechanical properties against the standard:
Yield strength ≥ 555MPa, tensile strength 625-825MPa, flexural strength ratio ≤ 0.93, and the metric conversion value of X80 (552MPa) is highly compatible.
2. International standard (ISO/EN)
Standard name: ISO 3183-2019 Steel pipes for pipeline transmission system in oil and gas industry
Equivalent grade: L555M (PSL2)
Application scope: Used in the same way as API 5L X80 for onshore and offshore oil and gas transmission pipelines to meet the requirements of low-temperature toughness (e.g. -20℃ impact work ≥40J) and corrosion resistance.
3. Other regional standards
European Standard (EN): L555MB in EN 10208-2 for high pressure pipelines in acidic environment (e.g. containing H₂S).
Russian standard (GOST): K60 (corresponding to X80), but the alloy design is slightly different, need to be verified with specific projects.
