What is Q345 steel?
A: Q345 is a low-alloy high-strength structural steel. Q represents yield strength, and 345 indicates a yield strength ≥ 345 MPa (≤16mm thickness). It has good comprehensive mechanical properties, high strength, and excellent toughness and weldability.
What grades of Q345 are commonly used in bank buildings?
A: Commonly used grades are Q345B, Q345C, and Q345D. Grade B (20℃ impact resistance), Grade C (0℃), and Grade D (-20℃) are used for load-bearing, earthquake-resistant, and low-temperature areas.
Q345 vs Q235: Why is Q345 chosen for bank buildings?
A: Q345 has approximately 30%–50% higher strength than Q235. Under the same load, it has a smaller cross-section and is lighter (reduced by 15–30%), improving earthquake resistance, blast resistance, and impact resistance, meeting the high security requirements of banks.
How does the strength of Q345 change with thickness? A: The strength decreases slightly with thickness:
≤16mm: ≥345MPa
16–40mm: ≥335MPa
40–63mm: ≥325MPa
63–100mm: ≥315MPa
What are the common specifications for Q345 steel in bank construction?
A: Steel plates 8–50mm thick, H-beams, I-beams, angle steel, round steel, and seamless pipes, used for beams, columns, supports, counters, vault reinforcement, and protective structures.