Abstract: Equal angle steels measuring 200 mm side width by 10 mm side thickness,made of Q460C steel,exhibited cracks at the edge. The metallographic examination and energy dispersive spectroscopy(EDS) analysis were performed on the cracked angle steel. The hot rolling process of the angle steel was simulated by Abaqus finite element method,and the hot plasticity of Q460C steel billets was investigated through simulative test. The results showed that(a) a small amount of MnS inclusions measuring less than 5 μm was present in the cracked angle steel,but were not the cause for its cracking;(b) there was a 50 to 100 μm thick decarburized layer at the crack of the angle steel,which formed during heating for rolling; and(c) Q460C steel billets exhibited good hot plasticity in the temperature range of 975 to 1 000 ℃,however,the cracks originated at the inner arc corner of the casting blank because of the nonuniform cooling of the continuous casting mould,thus resulting in edge cracking of the equal angle steels after rolling. The percentage of Q460C equal angle steels whose edge cracked decreased from 12% to nil by the increase in both the fillet radius of the mould and the thickness of the copper tube corner.