Acta Metallurgica Sinica (English Letters) ›› 2018, Vol. 31 ›› Issue (10): 1038-1048.DOI: 10.1007/s40195-018-0767-8

• Orginal Article • Previous Articles     Next Articles

Effect of Pre-deformation on Grain Ultrafining by Intercritical Deformation in Low-Carbon Microalloyed Steels

Ba Li1(), Qing-You Liu1, Shu-Jun Jia1, Yi Ren2, Bing Wang1   

  1. 1 Central Iron and Steel Research Institute, Beijing 100081, China
    2 Iron and Steel Research Institute, Ansteel Group Co., Ltd., Anshan 114009, China
  • Received:2018-06-22 Revised:2018-06-22 Online:2018-10-10 Published:2018-10-30

Abstract:

In this study, the effect of pre-deformation at recrystallization and non-recrystallization zone on the grain ultrafining by the subsequent intercritical deformation (ID) was investigated on low-carbon microalloyed steel. The results showed that ultrafine grain microstructure with an average size of?~?1.0 μm was fabricated through pre-deformation in the recrystallization zone followed by ID. When pre-deformed at the non-recrystallization zone prior to ID, the grain size increased to 1.6 μm with a heterogeneous distribution along with the well-developed dynamic recovery of ferrite. The grain ultrafining mechanism was attributed to the combined action of the deformation-induced ferrite transformation and the continuous dynamic recrystallization. In particular, the continuous dynamic recrystallization process during ID occurred on the pro-eutectoid ferrite as a result of the subgrain rotation mechanism and the absorbing dislocations mechanism.

Key words: Low-carbon microalloyed steels, Intercritical deformation, Ultrafine grain, Continuous dynamic recrystallization, Deformation-induced ferrite transformation