型号编辑Q345A：C≤0.20，Mn ≤1.70，Si≤0.50，P≤0.035，S≤0.035；Q345B：C≤0.20，Mn ≤1.70，Si≤0.50，P≤0.035，S≤0.035；Q345C：C≤0.20，热镀锌栏杆钢插芯加工，Mn ≤1.70，Si≤0.50，P≤0.030，海口加工，S≤0.030，Al≥0.015；Q345D：C≤0.18，Mn ≤1.70，Si≤0.50
