顾超, 赵立华, 甘鹏. 超低碳钢精炼过程中Fe-Al-Ti-O类复合氧化物夹杂的演变与控制[J]. 工程科学学报, 2019, 41(6): 757-762. DOI: 10.13374/j.issn2095-9389.2019.06.007
引用本文: 顾超, 赵立华, 甘鹏. 超低碳钢精炼过程中Fe-Al-Ti-O类复合氧化物夹杂的演变与控制[J]. 工程科学学报, 2019, 41(6): 757-762. DOI: 10.13374/j.issn2095-9389.2019.06.007
GU Chao, ZHAO Li-hua, GAN Peng. Revolution and control of Fe-Al-Ti-O complex oxide inclusions in ultralow-carbon steel during refining process[J]. Chinese Journal of Engineering, 2019, 41(6): 757-762. DOI: 10.13374/j.issn2095-9389.2019.06.007
Citation: GU Chao, ZHAO Li-hua, GAN Peng. Revolution and control of Fe-Al-Ti-O complex oxide inclusions in ultralow-carbon steel during refining process[J]. Chinese Journal of Engineering, 2019, 41(6): 757-762. DOI: 10.13374/j.issn2095-9389.2019.06.007

超低碳钢精炼过程中Fe-Al-Ti-O类复合氧化物夹杂的演变与控制

Revolution and control of Fe-Al-Ti-O complex oxide inclusions in ultralow-carbon steel during refining process

  • 摘要: 超低碳钢是一种重要的汽车用钢材料, 钢中通常添加钛元素, 使其形成析出物, 提高钢材的深冲性.然而钛元素作为一种脱氧能力较强的元素, 进入钢液中通常首先形成氧化物.为了减少含钛氧化物夹杂的生成, 基于"转炉-RH-连铸"的超低碳钢生产流程, 对RH精炼过程进行系统取样, 分析了铝脱氧剂加入后及合金化元素钛加入后的氧、氮气体含量变化及夹杂物特征变化, 并使用FactSage热力学计算软件对Fe-Al-Ti-O夹杂物稳定相图进行计算.研究结果显示, 含钛类氧化物夹杂通常以Al2O3类夹杂物作为形核质点, 对其形成包裹状夹杂物.若避免含Ti夹杂物的生成, 当钢中Ti质量分数为0.1%时, 钢中溶解Al质量分数应在0.01%以上.对含钛氧化物的生成及长大流程进行研究, 通过对Al2O3夹杂物及Ti2O3夹杂物粗化率的计算及附着功的比较可知, Ti2O3夹杂物在1600℃时的熟化生长速率较Al2O3较大且Ti2O3夹杂物与Al2O3夹杂物相比不容易相互碰撞融合并从钢液中去除.若提高精炼过程中的氧化物夹杂物去除率, 应严格控制含钛氧化物类夹杂物的生成.

     

    Abstract: Ultralow-carbon steel is an important material for automobile production. Titanium is usually added in this steel grade to form a precipitant and improve the deep drawing property of the steel. However, due to the deoxidation capacity of Ti, Ti addition will directly generate Ti-bearing oxide inclusions instead of the precipitant. To reduce the amount of Ti-bearing oxide inclusions, samples were collected during the RH refining based on the basic oxygen furnace-Ruhrstahl-Heraeus reactor-continuous casting (BOF-RH-CC) ultralow-carbon steel production process, and the oxygen content and inclusion characterization after Al addition and Ti addition were analyzed. The thermodynamics calculation software FactSage was adopted to calculate the Fe-Al-Ti-O inclusion stability phase diagram. The results show that the Al2O3 inclusion usually acts as the nucleation point of the Ti-bearing oxide inclusion, which wraps the Al2O3 inclusion to form the Al-Ti-O complex inclusion. To avoid the generation of the Ti-bearing oxide inclusions, the mass fraction of dissolved Al in the molten steel should be greater than 0.01% when the Ti mass fraction is 0.1%. Furthermore, the generation and growth behavior of the Ti-bearing oxide inclusion were also studied. Based on the calculation of the growth rate and the comparison of the adhesion work of the Al2O3 inclusion and the Ti2O3 inclusion, it is concluded that the growth rate of Ti2O3 inclusion is greater than that of Al2O3 inclusion, and it is more difficult for Ti2O3 inclusions to collide with each other and to be removed at 1600℃. Therefore, the generation of Ti-bearing oxide inclusions should be strictly controlled to improve the removal rate of oxide inclusions in ultralow-carbon steels.

     

/

返回文章
返回