
Metal
GB Q345B | S355JR
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Q345 is a low-alloy high-strength structural steel. By incorporating multiple microalloying elements, it achieves significantly enhanced strength while maintaining excellent weldability and toughness. Compared to ordinary carbon steels (such as Q235), Q345 has higher load-bearing capacity and superior impact resistance, and is widely used in construction structures, mechanical structural components, and other fields.
345 - 400 MPa
470 – 630 MPa
22% - 28%
140 - 180 HB
205 - 210 GPa
350 - 400 °C
48 - 52 W/(m·K)
11.5 - 12.5 μm/(m·°C)
7.85 g/cm³
20 - 25 μΩ·cm
poor
Excellent