Abstract: 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.

Key words: Steel Tire Cord, CaO-MgO-SiO₂-Al₂O₃ Series, Deformability of Inclusions, Breakage Ratio

摘要： 通过分析70 t转炉流程和180 t转炉流程生产的LX72A帘线钢合股断丝率,得出中心偏析相同的条件下,当钢中脆性夹杂物比例由90.7%降至20.5%,也就是塑性夹杂物的比例由9.3%提高79.5%时,平均盘条断丝率由4.20次/t降至2.56次/t。通过采用碱度1.05不含MgO的LF精炼渣,控制钢中Als含量≤0.001%,氧含量≤22×10^-6,可有效地降低钢中脆性夹杂物含量,降低盘条断丝率。

关键词: 帘线钢, CaO-MgO-SiO₂-Al₂O₃系, 夹杂物塑性化, 断丝率