炼钢 ›› 2025, Vol. 41 ›› Issue (2): 85-91.

• 凝固与浇铸 • 上一篇    下一篇

结晶器液渣层厚度对大方坯表面质量的影响

程  朋1,文光华1,李秋平1,陈远清2,李成斌2,刘  洋2   

  1. 1.重庆大学 材料科学与工程学院,重庆 400044;
    2.江苏永钢集团有限公司,江苏 张家港 215628
  • 出版日期:2025-04-05 发布日期:2025-04-02

Effect of  the thickness of the liquid slag layer in the mold on surface quality of bloom

  • Online:2025-04-05 Published:2025-04-02

摘要: 为了提高某厂连铸大方坯的表面质量,对铸坯表面裂纹、气孔缺陷进行分析并对连铸现场保护渣使用情况进行跟踪。结果表明,在缺陷周围发生明显脱碳行为,原始奥氏体晶粒大小较正常位置更加粗大,结晶器内保护渣液渣层厚度整体较薄。通过对保护渣加渣高度进行调整进而优化保护渣的熔化速率以此增加液渣层厚度。优化后,液渣层厚度较之前整体提高,裂纹发生率明显下降。对轧材进行漏磁探伤,研究钢种合格率由51.6%提升到94.0%。

关键词: 大方坯, 表面质量, 保护渣, 液渣层厚度, 熔化速率

Abstract: In order to improve the surface quality of continuous casting bloom in a factory, the surface cracks and porosity defects of bloom were analyzed and the use of mold flux was tracked. The results show that obvious decarburization occurs around the defect, the original austenite grain size is larger than the normal position, and the thickness of the liquid slag layer of the mold flux is relatively thin. By adjusting the height of mold flux, the melting rate of mold flux is optimized to increase the thickness of liquid slag layer. After optimization, the thickness of liquid slag layer was higher than before, and the incidence of cracks was obviously reduced. Magnetic flux leakage testing was carried out on the rolled products, and the qualified ratio of the studied steel grades increased from 51.6% in the previous period to 94.0%.

Key words: bloom, surface quality, mold flux, thickness of liquid slag layer, melting rate