1. Corresponding domestic grades
GB/T 8163 standard: 20# seamless steel pipe (chemical composition and mechanical properties are highly compatible with L245).
GB/T 9711 standard: L245 steel pipe directly corresponds to the domestic oil and gas pipeline steel, emphasising its low carbon and low sulphur and phosphorus characteristics.
2. Differences and similarities with No. 20 steel
Composition comparison:
L245: C ≤ 0.26%, Mn ≤ 1.15%, S / P ≤ 0.03%, yield strength ≥ 245 MPa, tensile strength ≥ 415 MPa.
No. 20 steel: C 0.17-0.24%, Mn 0.35-0.65%, yield strength ≥245 MPa, tensile strength ≥410 MPa.
Points of difference: L245 has a higher manganese content and stricter control of impurities, more suitable for high-pressure fluid transport.
Substitutability:
They can be substituted for each other in general pressurised pipelines, but they need to be carefully evaluated when they are involved in high-pressure, low-temperature or corrosive environments.
3. International Standard Correlation
ASTM A53/A106: The performance of L245 is close to that of Gr.B seamless steel pipe, but it should be noted that the carbon content is slightly higher.
4. Application Scenarios
Oil and gas transmission: L245N is widely used in low-pressure fluid pipelines (e.g. natural gas gathering lines).
Mechanical structure: replacing No.20 steel to manufacture shafts, brackets and other non-high-strength parts.
