Fracture reason of Q355B tower angle steel

During the operation of a tower, the angle steel between the connecting base and the tower rod broke. The fracture angle steel was analyzed by means of macroscopic observation, chemical composition analysis, metallographic examination, mechanical property test, scanning electron microscope and energy spectrum analysis. The results show that the content of P element in the angle steel exceeded the standard value, which reduced the cold plastic deformation ability of the angle steel and enhanced the cold brittleness of the steel. There were many non-metallic inclusions in the material, which weakens the continuity of the material. The fracture form of angle steel was brittle cleavage fracture.