电工钢 ›› 2020, Vol. 2 ›› Issue (4): 13-.

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薄板坯连铸无取向电工钢表面横裂纹分析

陈振文   

  1. 涟源钢铁集团有限公司,湖南 娄底 417000
  • 出版日期:2020-10-28 发布日期:2020-10-29

Analysis of surface transverse crack in continuous casting thin slab of nonoriented electrical steel 

CHEN Zhenwen   

  1.  Lianyuan Iron and Steel Group Co.,Ltd.,Loudi 417000,China
  • Online:2020-10-28 Published:2020-10-29

摘要: 对无取向电工钢横裂纹进行了检测分析,调查了电工钢生产过程中的连铸工艺状况,包括扇形段压力、二冷强度、增压泵、液芯压下等,进行了不同工艺的比较分析。结果表明:无取向电工钢表面横裂纹产生的根源是由于钢中P元素的偏析造成晶界脆性,降低了钢的高温塑性,带液芯的铸坯在扇形1段受到的热应力或机械应力超出了该钢种在此高温区的临界应力所致。在提高扇形1段设备精度,减缓1段二次冷却后,表面横裂纹得到了有效控制。

关键词: 横裂纹, 二冷强度, 偏析, 晶界脆性

Abstract: The transverse crack in non-oriented electrical steel was tested in this paper, and the continuous casting technology in production process, including the pressure of fan-shaped section, secondary cooling strength, booster pump, liquid core reduction, was investigated and analyzed. The results showed that the causes of the surface transverse crack in nonoriented electrical steel was the segregation of phosphorus element in steel, which caused the grain boundary brittleness and reduced the high temperature plasticity of steel, and the thermal or mechanical stress of the slab with liquid core in No. 1 fanshaped section exceeding the steel’s threshold stress at elevated temperature. The surface transverse crack has been effectively controlled since increasing the equipment precision of No. 1 fanshaped section, and  slowing down the secondary cooling  of No. 1 fanshaped section.

Key words: transverse cracks, secondary cooling intensity, segregation, grain boundary brittleness