Estimations of the True Stress and True Strain until Just before Fracture by the Stepwise Tensile Test and Bridgman Equation for Various Metals and Alloys

Abstract

True stress (s) true strain (e) relationships until just before fracture, i.e., the plastic deformation limit, were estimated by the stepwise tensile test and the Bridgman equation for various metals and alloys with different crystal structures. The estimated s e relationships were different from the nominal stress strain curves including the conventional tensile properties. In the relationships between the true stress (s pdl ) and true strain (e pdl ) at the plastic deformation limit, SUS304 and SUS329J4L indicated a better s pdl  e pdl balance. On the other hand, SUS329J4L, tempered martensite, and an ultrafine grained steel showed superior results in the yield strength e pdl balance. The estimated s e relationship for the ultrafine grained steel suggests that grain refinement strengthening can improve s and e up until the plastic deformation limit. The value of e pdl became larger with increasing the reduction in area and a decrease in the fracture stress. The products of s pdl and e pdl became larger with increasing work hardening rate at the plastic deformation limit.

Toughening of Low-Alloy Steel by Ultrafine-Grained Structure (Development of Fracture Control from Microstructure Design)

“…However, the TF and TFA samples had superior uniform elongation, as well as reduction in area. Such superior tensile-ductility balance has been seen for other warm rolled steels with different compositions [15,19,20]. Similarly, steel wires with UFEG structures, dominated by a strong α-fiber texture, exhibit superior tensile ductility despite their high strength [21].…”

A quantitatively accurate theory of stable crack growth in single phase ductile metal alloys under the influence of cyclic loading

“…It has been shown that a power law hardening relationship can describe large plastic strains reasonably well, when fit to true stress−true strain data. Tsuchida et al (2012) To validate this work, it is compared to a variety of materials at different stress ratios.…”