Disqualification Reasons Analysis on Tensile Properties of Q345B Steel Plates

By using optical microscope, scanning electron microscope and energy dispersive spectrometer, the tensile properties disqualification reasons of Q345B steel plates were analyzed. The results show that the existence of a large number of flake defects, tiny cracks and sulfide inclusions at the center segregation band, was main reason for the disqualification of tensile properties of Q345B steel plates. At the same time, the Widmanstatten structure also had a negative impact on the extension of the steel plates. Finally, according to the disqualification reasons, improvement measures were put forward.