GB 700 Q255A Introduce
The GB 700 Standard, also known as the Chinese Steel Standard, is the Chinese steel product standard which has been adopted by the People's Republic of China since 1949. The standard was formulated following the advances made in steelmaking during the second half of the 19th century and has been adopted by many countries in the world in terms of steel product classification, quality, marking and testing. It encompasses the quality requirements for all types of steel products within its scope, including the production and processing of steel, design and construction, inspection, testing and certification.
Smelting temperature:1657°C - 1879°C
Application:Carbon structural steel
GB 700 Q255A Material Chemical Composition
The chemical composition of the GB 700 Q255A steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 0.3000 |
| Sulfur (S) | - | 0.0500 |
| PhOsphorus (P) | - | 0.0450 |
| Nickel (Ni) | - | 0.3000 |
| Manganese (Mn) | 0.4000 | 0.7000 |
| Copper (Cu) | - | 0.3000 |
| Chromium (Cr) | - | 0.3000 |
| Carbon (C) | 0.1800 | 0.2800 |
GB 700 Q255A Material Mechanical Properties
The mechanical properties of the GB 700 Q255A steel are as follows:
| YieldRp0.2 | ≤ 235 (MPa) |
| TeileRm | ≤ 599 (MPa) |
| ImpactKV/Ku | 23(J) |
| ElongationA | 13% |
| Reduction in cross section on fractureZ | 11% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 313 |
GB 700 Q255A Material Thermal Properties
The thermal performance parameters of the GB 700 Q255A steel are as follows:
| Temperature (°C) | 11 | 716 | 449 |
| Modulus of elasticity (GPa) | - | 837 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 12 |
| Thermal conductivity (W/m·°C) | - | 11.3 | 33.2 |
| Specific thermal capacity (J/kg·°C) | - | 311 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.14 | - | - |
| Deity (kg/dm³) | - | - | 211 |
| Poisson’s coefficient, ν | - | - | 144 |