›› 2016, Vol. 32 ›› Issue (3): 67-72.

• 产品工艺与质量控制(含特钢) • 上一篇    下一篇

亚包晶钢连铸坯角部横裂纹控制研究

李树森1,2,张立峰3,杨小刚3,李明1,2   

  1. 1. 北京科技大学冶金与生态工程学院
    2. 首钢股份公司迁安钢铁公司
    3. 北京科技大学
  • 收稿日期:2015-11-25 修回日期:2016-02-05 接受日期:1900-01-01 出版日期:2016-06-05 发布日期:2016-06-15
  • 通讯作者: 杨小刚 E-mail:ustbyangxg@163.com
  • 基金资助:
    中国自然科学基金

Control of transverse corner cracks on hypoperitectic steel slabs

  1. 1. Qian’an Steelmaking Co. Ltd., Shougang Group
    2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing
    3. University of Science and Technology Beijing
  • Received:2015-11-25 Revised:2016-02-05 Accepted:1900-01-01 Online:2016-06-05 Published:2016-06-15

摘要: 为了提高亚包晶钢连铸坯表面质量,运用低倍显微观察以及模拟等手段对亚包晶钢连铸坯角部横裂纹的形成机理进行了研究,研究结果表明:不同钢种角部横裂纹附近组织不一,碳含量为0.15%的钢种裂纹附近组织为均匀的铁素体+珠光体,而碳含量为0.093%的钢种的裂纹主要发生在厚度约50μm的沿晶先共析铁素体薄膜上,后者裂纹的发生率约为前者的3倍;碳含量对钢种塑性有根本性影响,从而影响角部横裂纹的发生,工业试验结果表明在碳含量低于0.1%范围内,将碳含量降低至0.07%,角部横裂纹的发生率可由原来的44%降低至约4%。二冷数值模拟优化结果表明,优化采用的弯曲段前弱冷模式及弯曲段之后内弧强冷模式的冷却方案可保证连铸坯内外弧角部温度均避开第III脆性区,优化后裂纹数量及长度大幅度降低,角部横裂纹的发生可得到良好控制。

关键词: 裂纹, 先共析铁素体, 降低碳含量, 二冷优化

Abstract: In this article, various means were used to study the influence factors and control of transverse corner cracks on hypoperitectic steel slabs for improving the slab surface quaility. The microstructures implicated that proeutectoid ferrites along austenite grain boundaries could increase two times of the occurrence fraction of cracks. The carbon content makes an essential influence on the hot ductility of steel. Reduce carbon content to 0.07% could sharp reduce the cracks occurrence fraction from 44% to about 4% in the carbon cotent range less than 0.1%. A secondary cooling scheme of a weak cooling intensity before the bending segment and followed by an strong cooling intensity at the straightening segments was suggested and was proved to be effective in eliminating transverse corner cracks, both the cracks number and length were markly reduced.

Key words: cracks, proeutectoid ferrites, reduce carbon content, optimizing secondary cooling water amount

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