东北大学学报:自然科学版 ›› 2018, Vol. 39 ›› Issue (4): 497-500.DOI: 10.12068/j.issn.1005-3026.2018.04.009

• 材料与冶金 • 上一篇    下一篇

双辊薄带连铸低碳微合金钢的铸态组织

王鹤松, 袁国, 曹光明, 王国栋   

  1. (东北大学 轧制技术及连轧自动化国家重点实验室, 辽宁 沈阳110819)
  • 收稿日期:2016-11-21 修回日期:2016-11-21 出版日期:2018-04-15 发布日期:2018-04-10
  • 通讯作者: 王鹤松
  • 作者简介:王鹤松(1992-),男,辽宁鞍山人,东北大学博士研究生; 袁国(1979-),男,山东泰安人,东北大学教授,博士生导师; 王国栋(1942-),男,辽宁大连人,东北大学教授,博士生导师,中国工程院院士.
  • 基金资助:
    国家自然科学基金资助项目(51171041).国家自然科学基金资助项目(51504063).

As-Cast Microstructures of Low-Carbon Microalloyed Steel Produced by Twin-Roll Strip Casting

WANG He-song, YUAN Guo, CAO Guang-ming, WANG Guo-dong   

  1. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
  • Received:2016-11-21 Revised:2016-11-21 Online:2018-04-15 Published:2018-04-10
  • Contact: YUAN Guo
  • About author:-
  • Supported by:
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摘要: 采用双辊薄带连铸技术制备了低碳微合金钢薄带,利用OM,SEM和TEM对铸态凝固组织、室温组织、析出及位错进行观察和分析.结果表明:低碳微合金钢铸带的凝固组织中二次枝晶间距约为12~15μm,相对于传统厚板坯和薄板坯连铸,铸带组织得到了明显细化.铸带的原奥氏体晶粒尺寸比较粗大,约为250~410μm,其组织由魏氏铁素体、珠光体和不规则铁素体组成.铸带组织中存在纳米级TiC析出和短棒状的渗碳体.TiC析出没有被薄带连铸的凝固过程及二次冷却过程明显抑制.铸带组织由于铸轧力及二次冷却速率不均匀导致大量位错的产生.

关键词: 双辊薄带连铸, 低碳微合金钢, 凝固组织, 原奥氏体晶粒, 析出

Abstract: Low-carbon microalloyed steel was produced via twin-roll strip casting in the laboratory. The solidification structure, microstructure at room temperature, precipitate and dislocation of the as-cast strip were analyzed by OM, SEM and TEM. The results showed that the secondary dendrite arm spacing of the solidification structure is in the range of 12~15μm, which is much finer than that of the slab produced by the traditional process. The prior austenite grain of the as-cast strip is quite coarse with a size range of 250~410μm. The microstructure of the as-cast strip consists of Widmanstatten ferrite, pearlite and irregular ferrite. The nano-sized TiC precipitate and rod-like cementite are observed in the as-cast structure. The TiC precipitate in the as-cast strip is not obviously suppressed by the rapid solidification rate and secondary cooling rate (cooling in air) of the twin-roll strip casting. Furthermore, a large amount of dislocations in the as-cast strip are also observed, formed by rolling force among the casting rollers and nonuniform cooling rate of the second cooling process.

Key words: twin-roll strip casting, low-carbon microalloyed steel, solidification structure, prior austenite grain, precipitate

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