1. International Standard Equivalent Grades
American Standard System: Corresponding to X60 grade pipeline steel (API 5L standard).
Chinese standard:
L415M (GB/T 9711-2011): the suffix 'M' represents the delivery state of deformation heat treatment, equivalent to American Standard X60M.
L415Q: the suffix 'Q' indicates high quality grade, yield strength ≥ 415MPa, commonly used in high-pressure oil and gas pipelines.
2. Chemical composition and properties
Chemical composition:
Low carbon micro-alloyed steel, containing carbon (C) ≤ 0.18%, manganese (Mn) 0.3-1.0%, and add a small amount of chromium (Cr), molybdenum (Mo) and other elements to enhance corrosion resistance.
Mechanical properties:
Yield strength: ≥415 MPa (core index);
Tensile strength: 520-760 MPa;
Toughness requirements: need to meet the low-temperature impact absorption function standards, adapt to harsh environments.
3. Application areas
Oil and gas transmission: oil, natural gas long-distance pipeline, suitable for high-pressure, high corrosion scenarios;
Industrial pipeline: heat pipe network, chemical medium transport pipeline;
4. Technical characteristics
Welding performance: low hydrogen welding consumables are required and the preheating temperature (≥100℃) is controlled to reduce the risk of cold cracking;
Corrosion resistance: reduce HIC (hydrogen-induced cracking) and SSC (sulphide stress corrosion) sensitivity through micro-alloying process.
Summary: As a high-strength pipeline steel, L415 is equivalent to X60 (American Standard) and L415M (National Standard) in domestic and international standards, and is widely used in oil, gas, and industrial pipeline systems. and industrial pipeline systems, the core advantage of high yield strength and environmental corrosion resistance.
