Abstract: With the deoxidation by adding ferroaluminium and ferrosilicon in EAF tapping and the LF initial refining slag (/%:27.39~37.34 Al₂O₃，38.42~38.68 CaO，14.20~18.38 SiO₂，8.50~10.72 MgO，0.82~0.89 FeO，0.27~0.33 MnO，0.69~0.74 S，0.66~0.75TiO₂，（CaO）/（SiO₂）=2.09~2.72,（CaO）/（Al₂O₃）=1.04~1.40)_, at LF end point the T[O] is 0.0012% ~0.001 _{9% , the T[N] is 0.0043% ~0.0050% , and the [Ti] and [Ca] are respectively 0.002% and 0.006% ~ 0.009%. The analysis on oxide inclusions in bearing steel GCr15 at LF refining end show that the main oxide inclusions in steel are magnesia-alumina spinel (} MgO·Al₂O_{3) and calcium oxide-niagnesium-alumina spinel (}CaO·MgO·Al₂O_{3) ； the average size of magnesia-alumina spinel is less than 0. 5μm, and as MnS, TiN etc precipitated on them the average size increases； the average size of calcium oxide-inagnesia-alumina is normally more than 2μm and in refining temperature this inclusions are liquid state and easily aggregate and grow up, their size ( 1.39 〜2.12μm) is more than solid status calcium oxide-magnesia-alumina-MnS, so easily removed by floating up and absorbed by refining slag. With decreasing sulfur content in liquid during refining process, the average size of bearing MnS compound inclusions with core of magnesium-alumina and calcium oxide-magnesium-alumina spinel decreases. With suitable decrease of MgO content in refining end slag, optical basicity and viscosity of end slag the amount and average size of inclusions in steel shall be decreased.}

摘要： 通过电弧炉出钢加铝铁、硅铁脱氧,LF精炼初渣的组分为(/%:27.39~37.34 Al₂O_3，38.42~38.68 CaO，14.20~18.38 SiO_2，8.50~10.72 MgO，0.82~0.89 FeO，0.27~0.33 MnO，0.69~0.74 S，0.66~0.75TiO₂，（CaO）/（SiO₂）=2.09~2.72，（CaO）/（Al₂O₃）=1.04~1.40)，LF终点T[O]为0.0012%~0.0019%,T[N]为0.0043%~0.0050%，[Ti]0.002%和[Ca]0.006%~0.009%。GCr15轴承钢LF精炼终点氧化物夹杂分析结果表明，钢中主要氧化物夹杂为镁铝尖晶石（MgO·Al₂O₃）和钙镁铝尖晶石氧化物（CaO·MgO·Al₂O₃）。镁铝尖晶石平均尺寸低于0.5μm，当有MnS、TiN等在其上析出后平均尺寸增大。钙镁铝尖晶石平均尺寸通常在2μm以上，在精炼温度下呈液态，易在钢中聚集长大，其尺寸（1.39~2.12μm）比固态的钙镁铝尖晶石-MnS夹杂物大，且更被精炼渣吸收并上浮去除。随着精炼过程钢液中的硫含量降低，以这两类尖晶石为核心的含MnS的复合夹杂物的平均尺寸降低。适当降低精炼终点渣中MgO的含量、光学碱度和黏度可以减少钢中夹杂物的数量并降低其平均尺寸。

关键词: GCr15轴承钢, 60t, LF, 精炼渣, 氧化物夹杂, 析出行为