- 1. 北京科技大学工程技术研究院
- 2. 北京科技大学
摘要: 西昌钢钒厂由于转炉热量不足而以BOF-LF-RH-CC工艺生产IF钢，为探究RH强制脱碳与自然脱碳工艺生产IF钢精炼效果，本文采用生产数据统计、氧氮分析、夹杂物自动扫描、扫描电镜和能谱分析等手段进行了详细研究。结果表明：强制脱碳工艺RH结束渣中平均T.Fe含量比自然脱碳工艺低1.3%，强制脱碳工艺可降低钢包顶渣氧化性；在保证RH脱碳效果前提下，尽量提高转炉终点碳含量、降低钢液氧含量，通过RH精炼时采用强制吹氧脱碳工艺弥补钢中氧，可显著降低顶渣氧化性。自然脱碳工艺与强制脱碳工艺控制热轧板T.O含量均比较理想；与自然脱碳工艺相比，强制脱碳工艺可有效降低IF钢[N]含量，这与强制脱碳工艺真空室内碳氧反应更剧烈使CO气泡更多和气液反应面积更大有关。脱碳工艺对IF钢热轧板中夹杂物类型、尺寸及数量没有明显影响，夹杂物均以Al2O3夹杂为主，Al2O3-TiOx与其他类夹杂物较少，平均尺寸分别为4.5 μm、4.4 μm、6.5 μm，且钢中75%以上夹杂物尺寸在8 μm以下。在RH精炼过程中，尽量降低RH脱碳结束钢中[O]含量，有利于提高钢液洁净度。
Analysis of refining effect of IF steel produced by RH forced and natural decarburization process
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Abstract: Owing to the insufficient converter heat, IF steel is produced by BOF-LF-RH-CC process in Xichang Steel & Vanadium Plant. In this work, to explore the refining effect of IF steel produced by RH forced and natural decarburization process, standard analysis methods were employed by performing production data statistics, the total oxygen and nitrogen analysis, automatic scanning electron microscopy, scanning electron microscopy and energy spectroscopy. The results show that the average T.Fe content in ladle slag after RH treatment of the forced decarburization process is 1.3% lower than that of the natural decarburization process, and the forced decarburization process can reduce the oxidability of ladle top slag. On the basis of ensuring the RH decarburization effect, increasing the final carbon content and reducing the molten steel oxygen content in the converter as far as possible, and then using the forced oxygen blowing decarburization process to compensate for the molten steel oxygen content during RH refining, will significantly decrease the ladle slag oxidability. Both the natural decarburization process and the forced decarburization process are ideal to control the T.O content of hot rolled sheet. Compared with the natural decarburization process, the forced decarburization process can effectively reduce the [N] content of IF steel, which is related to the more violent carbon-oxygen reaction in the vacuum chamber of the forced decarburization process, resulting in more CO bubbles and larger gas-liquid reaction area. The decarburization process has no obvious influence on the type, size and number of inclusions in IF steel hot rolled sheet. Al2O3 are mainly inclusions, and Al2O3-TiOx and other inclusions are less, with the average size of 4.5 μm, 4.4 μm and 6.5 μm, respectively, and more than 75% of inclusions are within 8 μm in size. During RH refining process, reducing the [O] content in molten steel after RH decarburization as far as possible is beneficial to improve the cleanliness of molten steel.