Abstract: The formation and transformation of inclusion in aluminium killed steel during refining have been studied with extra low oxygen steel steelmaking by 140 t LD - LF - RH - CC flow sheet. A sufficient of aluminium was added in test steel during tapping in order to as soon as decrease solution oxygen in liquid steel, and CaO-Al₂O₃ refining slag series containing 3.00% ~ 8.42% SiO₂ were selected for Al₂0₃ transforming to calcium aluminate inclusion. Test results showed that the transformation trend of inclusion in liquid steel during secondary refining was pure Al₂O_3→spinel→CaO - Al₂O₃-MgO complex inclusions, the transformation of inclusion in heat with slag containing 8. 42% SiO₂ was slower than that in heat with slag containing 3. 00% SiO₂, and as CaO/Al₂O₃ of refining slag was 1. 60, most inclusions in steel transformed to low melting point CaO-Al₂O₃-MgO complex inclusions. The available ingredient of ladle refining slag is 55% - 60% CaO, 35% -40% Al₂O₃, 5% ~10% MgO.

摘要： 研究了140 t LD-LF-RH-CC流程冶炼超低氧钢时精炼过程铝脱氧钢中夹杂物的变化。试验钢出钢过程加足够的铝脱氧,以尽快降低钢液中溶解氧。为使Al₂O₃转变为钙铝酸盐夹杂,选用CaO-Al₂O₃精炼渣系,渣中含3.00%～8.42%SiO₂。结果表明,精炼时钢液中夹杂物的变化趋势为:纯Al₂O₃→尖晶石夹杂→CaO-Al₂O₃-MgO复合夹杂物,炉渣中8.42%SiO₂炉次夹杂物转变慢于3.00%SiO₂炉次;当炉渣CaO/Al₂O₃为1.60时,钢中夹杂物大多转变为低熔点CaO-Al₂O₃-MgO复合夹杂。精炼渣的成分控制应为(%):55～60CaO,35～40Al₂O₃, 5～10MgO。