Abstract: Based on the serious corner transversal cracks on SS400B steel slabs in certain steel plant of Angang Steel, to prevent creating hot rolled steel coil defects, the cause of corner transversal crack was analyzed. By taking relevant countermeasures, such as improving the performance of mold power, reducing the strength of second cooling and adjusting the arrangement of caster rollers, the corner crack problem of SS400B steel slab had been effectively controlled. The crack ratio had been dropped from 87.6 % to 9.7 %, the slab without clearance angle processing could meet the requirements of hot rolling process and the number of hot rolled steel coil defects were less than 20, then the hot rolled steel could meet the users’need.

Key words: boron bearing steel, slab, corner transversal crack