Prediction of dynamic recrystallisation behaviour of AISI type 4140 medium carbon steel

Abstract

The aim of the present work was to establish quantitative relationships between the ¯ow stress and the volume fraction of dynamic recrystallisation (DRX) as a function of processing variables such as strain rate, temperature, and strain for AISI type 4140 medium carbon steel, by means of torsion tests. Torsion tests were carried out in the temperature range 900 ± 1100°C and the strain rate range 5 . 0610 2 ± 5 . 0610 0 s 1 to study the high temperature softening behaviour. For the exact prediction of ¯ow stress, the effective stress ± effective strain curves were divided into two regions, the work hardening and dynamic recovery region and the DRX region. The ¯ow stress of the DRX region could be expressed in terms of the volume fraction of DRX. It was found that the calculated results were in agreement with the experimental ¯ow stress and microstructure of the steel for any deformation condition.MST/4895

Dynamic recrystallization behavior of a superaustenitic stainless steel containing 16%Cr and 25%Ni

“…The critical strain required for the initiation of DRX can be identified as the inflection point of the Â-curve (where [19][20][21][22]. One way to follow the microstructural events during hot deformation is monitoring the changes in the value of  with respect to strain or stress.…”

Effect of temperature and strain rate on the compressive deformation behavior of 42CrMo steel

“…Totik et al (2002) carried out a comparative study of the hot workability by hot torsion test of 42CrMo steel. Kim and Yoo (2002) established the quantitative relationships between the flow stress and the volume fraction of dynamic recrystallization (DRX) as a function of processing variables such as strain rate, temperature, and strain for AISI type 4140 medium carbon steel, by means of torsion tests. Despite large amount of efforts invested into the behaviors of 42CrMo steel, the hot compressive deformation behavior of 42CrMo steel need to be further investigated to perform numerical simulation of forging and establish the hot formation process parameters for 42CrMo steel.…”

Kinetics and Critical Conditions for the Initiation of Dynamic Recrystallization in 304 Stainless Steel

“…The relationship between the critical strain and the inflection point in the q-s curve has been confirmed by other workers. 9,10) In the present work, the latter method is applied to determine precisely the effect of the deformation parameters (specifically, strain rate and temperature) on the initiation of dynamic recrystallization in 304 stainless steel and the accompanying critical and peak strains. Some unusual behaviour found in this way is compared with that observed in a high-purity Cr-Ni alloy.…”