不同碱度低氧化铝精炼渣对弹簧钢夹杂物成分的影响

Effect of refining slag with different basicities and low alumina content on inclusion composition of spring steel

为了优化55SiCrA弹簧钢中夹杂物的组成和形态,采用热力学软件Factsage分别研究了CaO、SiO_2含量对CaO-SiO_2-Al_2O_3-MgO与CaO-SiO_2-Al_2O_3-MnO系相图低熔点区域面积的影响,研究结果表明:随着CaO和SiO_2含量的增加,CaO-SiO_2-Al_2O_3-MnO系相图低熔点区域面积分数逐步增大;在CaO-SiO_2-Al_2O_3-MgO系中,当CaO的质量分数为40%,SiO_2的质量分数为50%时,对应相图的低熔点区域面积最大。同时,研究了不同碱度的精炼渣对钢样中夹杂物的影响,结果表明:当精炼渣的Al_2O_3含量相同时,随着精炼渣碱度的增大,夹杂物中Al_2O_3的含量不断增加,其成分逐渐偏离低熔点区域。当精炼渣中Al_2O_3的质量分数为8%,碱度为1.2时,可得到低熔点的塑性夹杂物,形貌多为球形,尺寸在5μm以下。

To optimize the composition and morphology of inclusions in 55 SiCrA spring steel,the effect of CaO and SiO2 contents on the low melting point zone of CaO-SiO2-Al2O3-MgO and CaO-SiO2-Al2O3-MnO inclusions was studied by thermodynamic software Factsage.The results show that with increasing CaO and SiO2 content,the area percentage of low melting point inclusions of CaO-SiO2-Al2O3-MnO system increases.The CaO-SiO2-Al2O3-MgO system has the maximum area of low melting point inclusions when CaO and SiO2 contents are 40 mass%and 50mass%,respectively.Meanwhile,the effect of refining slag with different basicities on inclusion composition of spring steel was investigated.The results show that with increasing basicity of the refining slag,the Al2O3 content in inclusion increases under the condition of the same Al2O3 content in slag,and its composition gradually deviates from the low melting point zone.Plastic inclusion with low melting point can be obtained when the Al2O3 content in refining slag is 8mass%,and the basicity is 1.2.And the morphology of the plastic inclusion appears spherical which size is below 5μm.