Tensile strength range?
470–630 MPa (all thicknesses).
Elongation after fracture?
≥21% (A5).
Main chemical composition (wt%)?
C≤0.20; Si≤0.50; Mn: 1.00–1.60; P≤0.035; S≤0.035; Trace Nb/V/Ti alloying.
Difference from Q235?
Q235: Carbon steel, yield strength 235 MPa, low strength, low price;
Q345: Low alloy steel, yield strength 345 MPa, high strength, good toughness, excellent weldability.