Abstract

The recovery and recrystallization kinetics of 80% cold rolled ultra low carbon steel are investigated during isothermally annealing for temperature ranges 350–640 °C as a function of different annealing time. The recovery is assessed by magnetic coercivity (Hc), while the recrystallization is determined by mechanical hardness. At low temperature (350 to 520 °C) annealing, recovery dominates for long time (∼12 000 s), while the annealing at 550 °C/ 900s and 580 °C/ 300s causes the recrystallized nuclei formation . The recovery kinetics is introduced by differential rate equation, explaining the reduction in coercivity with the recovery progress and the variation of an activation energy from 41–113 kJ mol−1. The recrystallization kinetics is found faster at high annealing temperature 640 °C than 550 and 580 °C based on hardness measurement, justifying by apparent activation energy within 114–190 kJ mol−1. Furthermore, the recovery and recrystallization rate increase with different annealing time, consistent to the change of microstructures and grain boundary characteristics evaluated by the orientation imaging microscopy (OIM) of electron backscattered diffraction (EBSD).

Highlights

  • The annealing treatment of low carbon steel results in the formation of substructure and new strain free grains with low dislocation density by recovery and recrystallization stages, respectively

  • The recovery and recrystallization rate increase with different annealing time, consistent to the change of microstructures and grain boundary characteristics evaluated by the orientation imaging microscopy (OIM) of electron backscattered diffraction (EBSD)

  • With the increasing annealing temperature at 520 °C, the ferrite grains are mostly orientated towards the 〈001〉 and 〈111〉//ND during recovery stage (figure 1(b)), leading to subgrain fractions

Read more

Summary

13 January 2020

Siuli Dutta, Ashis K Panda , Amitava Mitra, Subrata Chatterjee and Rajat K Roy. At low temperature (350 to 520 °C) annealing, recovery dominates for long time author(s) and the title of the work, journal citation (∼12 000 s), while the annealing at 550 °C/ 900s and 580 °C/ 300s causes the recrystallized nuclei and DOI. The recovery kinetics is introduced by differential rate equation, explaining the reduction in coercivity with the recovery progress and the variation of an activation energy from 41–113 kJ mol−1. The recrystallization kinetics is found faster at high annealing temperature 640 °C than 550 and 580 °C based on hardness measurement, justifying by apparent activation energy within 114–190 kJ mol−1. The recovery and recrystallization rate increase with different annealing time, consistent to the change of microstructures and grain boundary characteristics evaluated by the orientation imaging microscopy (OIM) of electron backscattered diffraction (EBSD)

Introduction
Experimentation
Results and discussion
Conclusions

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.