According to the analysis on stranding breaking rate of steel LX72A tire cord produced by 70 t LD converter flow sheet and 180t bottom blowing converter flow sheet

it is obtained that at the condition with same center segregation rating

as ratio of brittleness inclusions in steel decreases from 90. 7% to 20. 5%

i. e. ratio of plasticity inclusions in steel increases from 9. 3% to 79. 5%

the average breaking rate of tire cord decreases from 4. 20 times/1 to 2. 56 times/1. By using LF refining slag no-contained MgO with basicity 1.05

controlling Als content in steel ≤0. 001% and oxygen content ≤22 x 10

-6

it is available to decrease the brittleness inclusions content in steel and decrease breakage ratio of tire cord.