摘要
采用金相显微镜和扫描电镜对螺纹钢典型内裂纹漏钢坯壳的形貌进行了观察分析,探讨了该类型漏钢的特征及演变过程。研究认为,杂质元素特别是硫的晶间偏析对钢的高温强度及裂纹路径的形成有着重要的影响;结晶器内,坯壳生长不均匀导致铸坯表面产生凹陷,对应位置坯壳厚度较薄,并诱发内裂纹形成;出结晶器后,薄弱的内裂纹处承受应力集中,发生裂纹扩展,情况严重时导致漏钢产生。通过降低钢中的S含量、调整浇铸工艺参数后,螺纹钢小方坯内裂纹漏钢发生率由6.32%降低到1.10%。
In order to explore the characteristics of the breakout shell and its evolution process for the thread steel, it was investigated by optical microscope and scanning electron microscope analysis. The results indicated that the intergranular segregation especially sulphur played an importan~ role in the high temperature mechanical property of the steel and the crack propagation path. In the mold, the inhomogeneous growth of shell would cause the occurrence of longitudinal depression and then induce the formation of internal crack. The weak positions of the billet would subject to stress concentration at the exit of mold,cracks tended to propagate and the breakout might happen in severe cases.By controlling the content of sulphur in steel, adjusting the appropriate process parameters, the breakout ratio of the thread steel decreased from 6.32 % to 1.10 %.
出处
《炼钢》
CAS
北大核心
2016年第1期62-65,共4页
Steelmaking
关键词
连铸
小方坯
漏钢
晶界偏析
内裂纹
continuous casting
billet
breakout
intergranular segregation
internal crack
