Columnar to equiaxed transition during solidification of small ingot by using electric current pulse

  • Jie LiEmail author
  • Jian-hong Ma
  • Chang-jiang Song
  • Zhi-jun Li
  • Yu-lai Gao
  • Qi-jie Zhai


A new approach to applying the electric current pulse (ECP) with parallel electrodes to the promotion of the transition from columnar crystal to equiaxed crystal and the improvement of macrosegregation was introduced. The ECP was applied to different stages of the solidification. The results showed that the application of the ECP in both the initial stage (the thickness of solidified shell reached 2 mm approximately) and the late stage (the thickness of solidified shell reached 14 mm approximately) of solidification can promote the columnar to equiaxed transition (CET). The analysis showed that during solidification, a large number of nuclei around the upper surface fell off due to ECP, which subsequently showered on the melt and impinged the growth front of the columnar crystal. Therefore, the CET occurred. In addition, this method was also employed to influence the solidification process of bearing steel, and the results showed that the structure was changed from columnar crystal to equiaxed crystal, indicating that ECP can enhance the homogeneity of structure and composition of bearing steel.

Key words

columnar to equiaxed transition solidification electric current pulse macrosegregation 


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Copyright information

© China Iron and Steel Research Institute Group 2009

Authors and Affiliations

  • Jie Li
    • 1
    Email author
  • Jian-hong Ma
    • 1
  • Chang-jiang Song
    • 1
  • Zhi-jun Li
    • 1
  • Yu-lai Gao
    • 1
  • Qi-jie Zhai
    • 1
  1. 1.Shanghai Key Laboratory of Modern Metallurgy and Materials ProcessingShanghai UniversityShanghaiChina

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