炼钢 ›› 2022, Vol. 38 ›› Issue (4): 54-62.

• 炉外精炼 • 上一篇    下一篇

精炼渣对U75V钢中非金属夹杂物影响的研究

朱  君1,2,杨吉春1,谌智勇2,樊志明1,张立峰3   

  1. 1.内蒙古科技大学 材料与冶金学院,内蒙古 包头 014010;
    2.内蒙古包钢钢联股份有限公司 炼钢厂,内蒙古 包头 014010;
    3.北方工业大学,北京 100144
  • 出版日期:2022-08-05 发布日期:2022-07-29

Study on the influence of refined slag on non-metallic inclusions in U75V steel

  • Online:2022-08-05 Published:2022-07-29

摘要:

研究了精炼渣碱度和渣中Al2O3含量对U75V钢中非金属夹杂物的影响。结果表明,精炼渣碱度对钢中夹杂物成分影响较大。在U75V钢精炼过程中,随着精炼渣碱度由1.4提升至2.0,钢中夹杂物的成分发生了较大变化。其中,平均w(CaO)43 %升高至62 %平均w(SiO2)w(MgO)w(Al2O3均有不同程度的下降,分别由37 %16 %4 %下降到29 %7 %2 %精炼渣碱度对U75V钢中夹杂物数密度影响较大碱度为1.4时,夹杂物数密度为2.95 个/mm2,随着碱度升高至1.8,夹杂物数密度降至1.42 个/mm2,继续升高精炼渣碱度,夹杂物数密度开始增大。精炼渣碱度为1.8时,钢中夹杂物数密度最小,此时的精炼渣更有利于夹杂物的去除。精炼渣中Al2O3含量对钢中夹杂物有重要影响。随着精炼渣中w(Al2O3)0升至3 %,夹杂物中CaOSiO2含量降低,MgOAl2O3含量升高;继续提升精炼渣中w(Al2O3)6 %,夹杂物中w(CaO)不再变化,稳定在40 %左右,而MgO SiO2含量略有降低,w(Al2O3)则升高至18 %左右。随着渣中Al2O3含量升高,钢中夹杂物数密度持续上升,且当渣中w(Al2O3)3 %增加至6 %时,夹杂物数密度增加了近1倍。因此U75V需要将精炼渣中w(Al2O3)控制在3 %以下。在生产过程中,应严格控制合金和造渣材料中的AlsAl2O3含量,减少进入炉渣中Al2O3含量,将炉渣碱度控制在1.8左右。

关键词:

精炼渣, 碱度, U75V, 渣中Al2O3含量, 非金属夹杂物

Abstract:

The effects of basicity of refining slag and Al2O3 content on non-metallic inclusions in U75V steel were studied. The results showed that the basicity of refining slag had a great influence on the inclusions in steel. In the refining process of U75V steel, with the increase of basicity of refining slag from 1.4 to 2.0, the composition of inclusions in steel  changed greatly. The average mass fraction of CaO increased from 43% to 62%, while the average mass fraction of SiO2, MgO and Al2O3 decreased from 37 %16 % and 4 % to 8 %, 9 % and 2 % respectively. The basicity of refining slag had a great influence on the number density of inclusions in U75V steel. When the basicity was 1.4, the number density of inclusion was 2.95/mm2. With the increase of basicity to 1.8, the number density of inclusion decreased to 1.42/mm2, and the number density of inclusion began to increase. When the basicity of refining slag was 1.8, the number density of inclusion in steel was the lowest, and the refining slag was more conducive to the removal of inclusion. Al2O3 content in refining slag had an important effect on inclusions in steel. With the increase of Al2O3 content from 0 to 3%, the contents of CaO and SiO2 in the inclusions decreased, while the contents of MgO and Al2O3 increased. The mass fraction of Al2O3 in the refining slag was increased to 6 %, and the mass fraction of CaO in the inclusion remained stable at about 40 %, while the content of MgO and SiO2 decreased slightly, and the mass fraction of Al2O3 increased to about 18 %. With the increase of Al2O3 content in slag, the number density of inclusion in steel increased continuously, and when Al2O3 mass fraction in slag increases from 3 % to 6 %, the number density of inclusion increased by nearly one time. Therefore, U75V needs to control the Al2O3 mass fraction in refining slag below 3 %. In the process of production, Als and Al2O3 content in alloy and slag-making materials should be strictly controlled, Al2O3 content in slag should be reduced, and basicity of slag should be controlled at about 1.8.

Key words:

refining slag, basicity, U75V, Al2O3 content in slag, non-metallic inclusion