Q: What are the main chemical compositions (mass fraction, %) of Q355 coil?
A: C≤0.20, Si≤0.55, Mn≤1.60, P≤0.035, S≤0.035; may contain microalloying elements such as Nb≤0.06, V≤0.12, Ti≤0.20, which are specifically adjusted according to the grade and thickness.
Q: What is the influence of thickness on the yield strength of Q355 coil?
A: ≤16mm ≥355MPa; 16-40mm ≥345MPa; 40-63mm ≥335MPa; 63-80mm ≥325MPa; 80-100mm ≥315MPa; 100-150mm ≥305MPa.
Q: What is the tensile strength range of Q355 coil?
A: 470-630MPa, slightly fluctuating with thickness and rolling process.
Q: What is the elongation requirement of Q355 coil?
A: Grade A/B ≥21%; Grade C/D/E ≥22%, ensuring formability and toughness.
Q: What are the low-temperature impact requirements of Q355D coil?
A: The longitudinal V-notch impact energy at -20℃ is ≥34J, suitable for outdoor structures in cold regions.