Through experiments and thermodynamic analysis

it is obtained that the main cause of the scab forming of rolled 10B21 steel is the average nitrogen content in steel being 127 x 10

-6

lead to the precipitation of fine BN and AIN inclusions at the austenite grain boundary at the comer of cast billet during cooling

increasing the crack sensitivity of the billet and forming the billet crack

the nitrogen content in steel can be stably controlled below 50 x 10

-6

by increasing the consumption of molten iron ≥ 920 kg/t

increasing the C-T-P ( Carbon-Temperature-Phosphorus) hit rate ≥ 85% at the end of die converter

discharging steel from the outlet round

healing number of times of LF ≤ 3 time

and ≤ 25 minutes casting. It can effectively prevent wire rod scarring of 10B21 steel after rolling to improve the yield of rolled steel and to reduce the production cost.