GB 712 Grade AH550 Introduce
GB 712 Grade AH550 is mainly used for shipbuilding and marine engineering structures, as well as some other high tensile strength steels. With good malleability, machinability and welding ability, GB 712 Grade AH550 is commonly used for shipbuilding, construction,building structure,pressure vessel and boiler, automobile, agriculture, railways, bridges and so on.
Smelting temperature:1524°C - 1692°C
Application:Structural steel for hull
GB 712 Grade AH550 Material Chemical Composition
The chemical composition of the GB 712 Grade AH550 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 0.5500 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0300 |
| Nitrogen (N) | - | 0.0200 |
| Manganese (Mn) | - | 1.7000 |
| Carbon (C) | - | 0.2100 |
GB 712 Grade AH550 Material Mechanical Properties
The mechanical properties of the GB 712 Grade AH550 steel are as follows:
| YieldRp0.2 | ≤ 951 (MPa) |
| TeileRm | ≤ 621 (MPa) |
| ImpactKV/Ku | 23(J) |
| ElongationA | 14% |
| Reduction in cross section on fractureZ | 31% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 342 |
GB 712 Grade AH550 Material Thermal Properties
The thermal performance parameters of the GB 712 Grade AH550 steel are as follows:
| Temperature (°C) | 33 | 177 | 977 |
| Modulus of elasticity (GPa) | - | 522 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 21 |
| Thermal conductivity (W/m·°C) | - | 44.3 | 32.2 |
| Specific thermal capacity (J/kg·°C) | - | 441 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.41 | - | - |
| Deity (kg/dm³) | - | - | 211 |
| Poisson’s coefficient, ν | - | - | 343 |