Unraveling the Effect of Deformation Temperature on the Mechanical Behavior and Transformation‐Induced Plasticity of the SUS304L Stainless Steel

Abstract

The behavior of the SUS304L metastable austenitic stainless steel during deformation above and below Md temperature is systematically studied. At temperatures higher than Md, linear temperature‐dependent relationships are observed for tensile strength and elongation; whereas below Md, a sharp increase in these parameters is identified. A pronounced transformation‐induced plasticity (TRIP) effect is observed when the amount of martensite in the necked region becomes significant, resulting in a maximum point in the work‐hardening plot and enhancement of strength–ductility balance.

Deformation-induced martensite in austenitic stainless steels: A review

“…The amount of deformation-induced martensite depends on the chemical composition [2,116,117], initial grain size [73,85,[117][118][119][120][121][122][123][124][125][126][127][128], deformation temperature [56,57,[129][130][131][132][133][134][135], strain rate [57,[136][137][138][139][140][141][142], stress state and strain state [57,137,[143][144][145][146][147][148][149], strain [150][151][152], applied magnetic field [153], etc. Among these parameters, the chemical composition and initial grain size of the austenite phase can be classified as the material factors while the rest of parameters are deform...…”

“…It can be also seen that at low temperatures, a high amount of martensite can be obtained at lower strains. Moreover, at high temperatures, it is not possible to obtain high martensite fractions [53,56,57]. In fact, at a high enough temperature (M d ), there is no strain-induced martensitic transformation.…”

“…It is well known that the amount of martensite formed during deformation has significant impact on the specimen elongation [53,56]. However, the situation might be more complicated [53,131,141,[188][189][190].…”

“…Moreover, the formation of martensite during deformation is responsible for the enhanced workhardening rate, the inhibition of necking, and increased uniform elongation. This is known as the transformationinduced plasticity (TRIP) effect and plays a major role in determining the mechanical properties of metastable ASSs [5,[53][54][55][56][57][58]. Furthermore, the grain refining process of cold deformation and reversion annealing is based on the formation of strain-induced martensite during deformation and its reverse transformation to fine-grained austenite during annealing, which is also known as the SIMRT process [1,2,40,54].…”

Effect of Warm Deformation on Mechanical Properties and Deformation Mechanism of Nano/Ultrafine‐Grained 304 Stainless Steel

“…[ 17,18 ] Therefore, to avoid martensite formation during the deformation process, increasing the deformation temperature above the M d point is necessary to study the warm forming of high‐strength plastic nano/ultrafine‐grained (NG/UFG) ASS. [ 19 ] Maintaining the excellent properties of cold‐rolled sheets during processing and forming has become the direction of ongoing efforts by scientific researchers. However, there are few studies on the warm formability of ASS after grain refinement.…”