The Influence of Initial Grain Size and Strain Sequence of Slab Hot Rolling on the Austenite Evolution of Peritectic Microalloyed Plate Steels

Abstract:

The influence of the strain sequence during slab hot rolling (also known as “roughing”) on the evolution of austenite in plain carbon, C-Mn-V and C-Mn-Nb-Ti-V steels was investigated. Reheating and roughing simulations were conducted in a Bähr deformation dilatometer using a constant austenitising temperature, constant soaking time and various heating rates and roughing strain sequences. Stress analysis was used to quantify the austenite softening behaviour and the prior austenite grain size was measured from quenched specimens. The austenite grains of the plain carbon steel were coarser than those of both microalloyed steels, with the C-Mn-Nb-Ti-V grade being the finest due to effective pinning of the grain boundaries. Pass strains greater than 0.2 were sufficient for initiation of dynamic recrystallisation (DRX) for the C-Mn and C-Mn-V steels and led to uniform austenite microstructure with austenite grain sizes less than 40µm after the roughing stage.

• Periodical: Advanced Materials Research (Volume 1019)
• Pages: 339-346
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1019.339
• Online since: October 2014
• Authors: Rorisang Maubane*, Kevin Mark Banks, Waldo Stumpf, Charles Witness Siyasiya, Alison Tuling
• Keywords: Austenite, DRX, Microalloyed, Roughing, Strain, Stress

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