BARC/PUB/2014/0652

 
 

Development of ultra-fine grained dual-phase steels: Mechanism of grain refinement during inter-critical deformation

 
     
 
Author(s)

Karmakar, A.; Misra, R. D. K.; Neogy, S.; Chakrabarti, D.
(MSD)

Source

Advanced Materials Research, 2014. Vol. 783-786: pp. 674-678

ABSTRACT

Heavy deformation of metastable austenite (below Ae3) or both austenite and ferrite in the two-phase region (between Ar3 and Ar1) has been found to develop ultra-fine ferrite grain structures with average grain sizes less than 3 μm. The sequence of different dynamic softening mechanisms involved in the grain refinement during heavy intercritical deformation, such as, dynamic recovery, dynamic recrystallization, and dynamic strain induced austeniteferrite transformation, has been analyzed by considering strain partitioning between austenite and ferrite. Grain refinement is expected to be dictated by dynamic strain induced transformation (DSIT) at higher deformation temperatures (>1100°C) and pronounced dynamic recovery of ferrite at lower deformation temperatures (<1100°C). Evolution of crystallographic texture was dependent on the grain refinement mechanism and gamma fiber components (ND//<111>) and alpha fiber components (RD//<110>) dominated the texture at higher and lower deformation temperatures, respectively.

 
 
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