Dataset Information

Micro-deformation evolutions of the constituent phases in duplex stainless steel during cyclic nanoindentation.

ABSTRACT: Cyclic elastoplastic deformation behaviors of austenite phase and ferrite phase in a duplex stainless steel were investigate by load-controlled cyclic nanoindentation with a Berkovich indenter. During the tests, the maximum penetration depth per cycle increased rapidly with cycle number at transient state, and reached stable at quasi-steady state. Plastic dissipated energy was quantitatively proved to be the driving force for the propagation of deformation zones during cyclic nanoindentation tests. Transmission electron microscopy combined with FIB was used to reveal the deformation mechanisms of both phases underneath indents with cycles. After quasi-static single loading, nucleation and concentration of dislocations were observed in both austenite phase and ferrite phase under the indenter. After cyclic loading, dislocations propagated to further regions in both phases. Besides, slip bands were generated within single nanoindentation and propagated during the subsequent cyclic nanoindentation. The sizes of the deformation regions for both phases under the indents after cyclic indentation observed by TEM were consistent with those calculated by the expansion model of spherical cavity.

SUBMITTER: Cui YY

PROVIDER: S-EPMC5906455 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Micro-deformation evolutions of the constituent phases in duplex stainless steel during cyclic nanoindentation.

Cui Yuan-Yuan YY Jia Yun-Fei YF Xuan Fu-Zhen FZ

Scientific reports 20180418 1

Cyclic elastoplastic deformation behaviors of austenite phase and ferrite phase in a duplex stainless steel were investigate by load-controlled cyclic nanoindentation with a Berkovich indenter. During the tests, the maximum penetration depth per cycle increased rapidly with cycle number at transient state, and reached stable at quasi-steady state. Plastic dissipated energy was quantitatively proved to be the driving force for the propagation of deformation zones during cyclic nanoindentation tes ...[more]

PMID: 29670162

Similar Datasets

Project description:We describe here the relationship between grain structure, deformation mechanism and fracture characteristics in an austenitic stainless steel. This was accomplished using the novel concept of phase reversion that enabled a wide range of grain size from nanograined/ultrafine grained (NG/UFG) to coarse-grained (CG) regime to be obtained in a single material through change in temperature-time annealing sequence. In the NG/UFG structure, a marked increase in abundance of stacking faults (SFs) and twin density with strain was observed that led to a decrease in the average spacing between adjacent SFs, thus converting stacking faults into twins. Twinning in NG/UFG structure involved partial dislocations and their interaction with the grain boundaries, including SF overlapping and the coordinated nucleation of partial dislocations from the grain boundaries. The plastic zone in the NG/UFG structure resembled a network knitted by the intersecting twins and SFs. With SFE ~30 mJ/m2, the minimum stress for twin nucleation was ~250?MPa for the experiment steel and the corresponding optimal grain size (dop) wa ~120?nm. In contrast, in the CG structure, strain induced martensite formation was the deformation mechanism. The difference in the deformation mechanism led to a clear distinction in the fracture behavior from striated fracture in high strength-high ductility NG/UFG alloy to microvoid coalescence in the low strength-high ductility CG counterpart. The underlying reason for the change in fracture behavior was consistent with change in deformation mechanism from nanoscale twinning in NG/UFG alloy to strain-induced martensite in the CG alloy, which is related to change in the stability of austenite with grain size. An analysis of critical shear stress required to initiate twinning partial dislocations in comparison to that required to nucleate shear bands is presented. The appearance of striated fracture in the NG/UFG alloy suggests a quasi-static step wise crack growth process.

Dataset Information

Micro-deformation evolutions of the constituent phases in duplex stainless steel during cyclic nanoindentation.

Publications

Micro-deformation evolutions of the constituent phases in duplex stainless steel during cyclic nanoindentation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets