铈对IF钢全流程夹杂物的转变机理研究

Study on Transformation Mechanism of Inclusions in Entire Process of IF Steel with Ce

通过工业试验,在IF钢冶炼过程RH阶段中添加铈铁合金,以改善汽车板钢的综合性能。对试验结果进行工业取样,通过SEM-EDS电镜、ASPEX夹杂物自动扫面、XRD以及热力学计算对冶炼全流程稀土型夹杂物类型、尺寸以及显微组织进行系统分析。结果表明从RH到铸坯再到轧材,稀土Ce会对Al2O3以及MnS等夹杂物进行变性,优先生成Ce2O3、Ce2O2S、CeO2等稀土型夹杂物,稀土类夹杂物从Al-O-Ce类逐渐转变为Al-O-Ce、Ce-O-S、Al-O-Ce-S类夹杂物,形状趋于球形和椭球形,尺寸在5μm以下。

The Ce-Fe alloy is added at the stage of RH in the process of smelting IF steel to improve the overall performances of automobile sheet steel through industrial tests.The industrial sampling was carried out for the test results so that the type,size and microstructure of rare earth inclusions in the entire process of smelting were systematically analyzed with the SEM-EDS electron microscope,ASPEX automatic scanning of inclusions,X-ray diffraction(XRD)and thermodynamic calculation.The results showed that such inclusions as Al2O3 and MnS could be modified with rare earth Ce from RH to slab and rolled products so that such rare earth inclusions as Ce2O3,Ce2O2S and CeO2 were preferentially formed,rare earth inclusions were gradually transformed from Al-O-Ce to such inclusions as Al-O-Ce,Ce-O-S and Al-O-Ce-S as well as the shape tended to be spherical and ellipsoidal and the size was below 5μm.