GB/T 9711 PSL2 Grade L555Q Introduce
GB/T 9711 is the standard of petroleum and natural gas industries, which specifies the steel pipe properties and materials, transportation technical conditions and test methods. Steel pipes must meet the requirements of GB/T 9711 PSL2 Grade L555Q before they can be put into use.
Smelting temperature:1122°C - 1428°C
Application:Oil and gas industry, steel pipe for pipeline transportation system
GB/T 9711 PSL2 Grade L555Q Material Chemical Composition
The chemical composition of the GB/T 9711 PSL2 Grade L555Q steel are as follows:
| Element | Min | Max |
|---|---|---|
| Sulfur (S) | - | 0.0150 |
| PhOsphorus (P) | - | 0.0250 |
| Manganese (Mn) | - | 1.9000 |
| Silicon (Si) | - | 0.4500 |
| Carbon (C) | - | 0.1800 |
GB/T 9711 PSL2 Grade L555Q Material Mechanical Properties
The yield strength of GB/T 9711 PSL2 Grade L555Q steel is also important as it defines the limit of the material's elasticity before it permanently deforms. The yield strength of the steel ranges anywhere from 320-480 MPa, with some grades having a yield strength of up to 550 MPa.
The mechanical properties of the GB/T 9711 PSL2 Grade L555Q steel are as follows:
| YieldRp0.2 | ≤ 796 (MPa) |
| TeileRm | ≤ 455 (MPa) |
| ImpactKV/Ku | 44(J) |
| ElongationA | 33% |
| Reduction in cross section on fractureZ | 14% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 143 |
GB/T 9711 PSL2 Grade L555Q Material Thermal Properties
The thermal performance parameters of the GB/T 9711 PSL2 Grade L555Q steel are as follows:
| Temperature (°C) | 43 | 343 | 366 |
| Modulus of elasticity (GPa) | - | 455 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 24 |
| Thermal conductivity (W/m·°C) | - | 12.3 | 32.2 |
| Specific thermal capacity (J/kg·°C) | - | 343 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.42 | - | - |
| Deity (kg/dm³) | - | - | 433 |
| Poisson’s coefficient, ν | - | - | 124 |
GB/T 9711 PSL2 Grade L555Q Material Machining Technology
The advantages of machining GB/T 9711 PSL2 Grade L555Q steel include improved product accuracy and precision, increased production efficiency, and reduced costs. In addition, the surface finish of the machined component can be enhanced, which can help to increase its longevity. On the other hand, the machining of GB/T 9711 PSL2 Grade L555Q steel can also lead to an increase in tool wear, an increase in residual stress, and even deformation of the part.