GB/T 1591 Q345D Introduce
Steel is an essential material in construction and engineering, and it is important to have a common understanding of how different steel grades are used. The Chinese government set the standard for steel classification in China with the introduction of the GB/T 1591 steel standard. This standard is designed to improve the industrialization of steel and safeguard China's economic and environmental interests.
Smelting temperature:1978°C - 1345°C
Application:Low alloy high strength structural steel
GB/T 1591 Q345D Material Chemical Composition
The chemical composition of the GB/T 1591 Q345D steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | - | 0.1800 |
| Silicon (Si) | - | 0.5000 |
| Manganese (Mn) | - | 1.7000 |
| PhOsphorus (P) | - | 0.0300 |
| Sulfur (S) | - | 0.0250 |
| Niobium (Nb) | - | 0.0700 |
| Vanadium (V) | - | 0.1500 |
| Titanium (Ti) | - | 0.2000 |
| Chromium (Cr) | - | 0.3000 |
| Nickel (Ni) | - | 0.5000 |
| Copper (Cu) | - | 0.3000 |
| Nitrogen (N) | - | 0.0120 |
| Molybdenum (Mo) | - | 0.1000 |
| (Als) | 0.0150 | - |
| Titanium (Ti) | 0.0200 | 0.2000 |
| Aluminum (Al) | 0.0150 | - |
| Niobium (Nb) | 0.0150 | 0.0600 |
| Vanadium (V) | 0.0200 | 0.1500 |
| Sulfur (S) | - | 0.0300 |
| Manganese (Mn) | 1.0000 | 1.6000 |
| Silicon (Si) | - | 0.5500 |
GB/T 1591 Q345D Material Mechanical Properties
The strength of GB/T 1591 Q345D steel is determined by its tensile strength, yield strength and elongation properties. The higher the grade, the higher the tensile strength and yield strength. The strength of the steel also increases with increasing temperature.
The mechanical properties of the GB/T 1591 Q345D steel are as follows:
| YieldRp0.2 | ≤ 314 (MPa) |
| TeileRm | ≤ 612 (MPa) |
| ImpactKV/Ku | 12(J) |
| ElongationA | 44% |
| Reduction in cross section on fractureZ | 13% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 321 |
GB/T 1591 Q345D Material Thermal Properties
The thermal performance parameters of the GB/T 1591 Q345D steel are as follows:
| Temperature (°C) | 11 | 735 | 576 |
| Modulus of elasticity (GPa) | - | 259 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 23 |
| Thermal conductivity (W/m·°C) | - | 43.3 | 11.2 |
| Specific thermal capacity (J/kg·°C) | - | 111 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.43 | - | - |
| Deity (kg/dm³) | - | - | 311 |
| Poisson’s coefficient, ν | - | - | 423 |
GB/T 1591 Q345D Material Machining Technology
GB/T 1591 Q345D, also known as low-alloy high-strength steel, is a kind of alloy structural steel developed and produced under the Chinese national standards developed and used for a long time. The main alloy elements are manganese, niobium, molybdenum, vanadium, chromium, and other various macro and trace elements. It is a kind of high-performance alloy steel which can be realized through smelting and refinement.