Effect of competing hardening and softening mechanisms on the flow stress curve modeling of ultra-low carbon steel at high temperatures

Work-hardening effect and strain-rate sensitivity behavior during hot deformation of Ti–5Al–5Mo–5V–1Cr–1Fe alloy

“…During large strains of hot deformation under given temperatures and strain-rates, strain-rate sensitivity becomes more obvious with flow stress decreased, as illustrated by Eq. (15). The torsion experiment of Ni alloy by Les et al [7] could also confirm this result.…”

“…By considering a homogeneous dislocation distribution, Kocks-Mecking [13] model has been widely employed to characterize its density variation as: where k denotes the dislocation multiplication coefficient, related to lattice constant and mechanical properties, $G/200 [14]. X represents dislocation annihilation coefficient, significantly depending on deformation parameters under thermal activation [15]. The annihilation coefficient X could be estimated by [16,17]:…”

Competition between work-hardening effect and dynamic-softening behavior for processing as-cast GH4720Li superalloys with original dendrite microstructure during moderate-speed hot compression

“…Ω represents dislocation annihilation coefficient, significantly depending on deformation parameters under thermal activation [14]. The annihilation coefficient Ω is estimated by [15,16] GMb k 0.89 / 4…”

Análise do comportamento mecânico de um aço estrutural através de ensaios de torção

“…Um método eficiente com custo relativamente reduzido é a utilização do ensaio de torção a quente, que consiste em uma técnica experimental capaz de reproduzir as condições de trabalho de conformação. Isso permite investigar os mecanismos que estão operando, através de curvas de escoamento plástico e do acompanhamento da evolução microestrutural [Jorge et al, 1993;Regone, 2001;Jorge et al, 2003]. Com a leitura do torque e do ângulo, é possível calcular a tensão e a deformação equivalentes.…”