Showing 2 results for Critical Strain
Golmahalleh O., Zarei-Hanzaki A.,
Volume 1, Issue 1 (3-2004)
Abstract
In principal, a proper combination of strength and ductility is achieved through micro component refinement in steels. This is particularly empowered with ferrite refinement down to micron sizes in ferrite pearlite engineering steels. The latter is achieved through various well-defined methods in which strain induced transformation (SIT) has shown spectacular capabilities. In the present study, to address the effect of thermo mechanical processing parameters on the (SIT) behavior, two plain carbon steels were studied through single pass rolling. This was carried out at the corresponding Ar_3 + 20°C temperature of the steels. The results indicated that the transformation behavior and ferrite morphology would be .strongly influenced by both the chemical composition (i.e., carbon content) and the amount of applied strain. Furthermore, a high volume fraction of very fine ferrite with mean grain size of less than 2 µm was obtained. This was attributed to the ferrite nucleation at deformation bands and serrated austenite grain boundaries.
M. Shaban Ghazani, A. Vajd, B. Mosadeg,
Volume 12, Issue 1 (3-2015)
Abstract
The aim of the present study is the prediction of critical conditions (including critical strain and flow stress)
for the initiation of dynamic recrystallization during thermo-mechanical processing of plain carbon steels. For this
propose, torsion tests were conducted at different temperature (1050, 1100 and 1150˚C) and strain rates (0.002, 0.02
and 0.2/s). All flow curves showed a peak stress indicating that dynamic recrystallization occurs during hot
deformation. The critical stress and strain were then determined based on change in strain hardening rate as a function
of flow stress. Finally, the effect of deformation conditions on these parameters was analyzed.
