Role of retained austenite on adiabatic shear band formation during high strain rate loading in high-strength bainitic steels

Jo, Min Cheol; Kim, Selim; Suh, Dong‐Woo; Hong, S.S.; Kim, Hoon Yub; Sohn, Seok Su; Lee, Sunghak

doi:10.1016/j.msea.2020.139118

Cited by 17 publications

(5 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their microstructure consists of ferrite, bainite, and dispersed retained austenite of different morphologies [ 7 , 8 , 9 ]. The mechanical stability of the retained austenite is related to its resistance against strain-induced martensitic transformation depending on grain size [ 10 , 11 ], morphology [ 12 , 13 ], type of surrounding phases [ 14 , 15 ], stress state [ 16 , 17 ], strain rate [ 18 , 19 , 20 , 21 ], and also on the stacking fault energy (SFE) affected by the deformation temperature [ 13 , 22 , 23 , 24 , 25 , 26 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Elevated Deformation Temperatures on Microstructural and Tensile Behavior of Si-Al Alloyed TRIP-Aided Steel

Kozłowska

Grajcar

2020

Materials

View full text Add to dashboard Cite

The influence of elevated deformation temperatures on the relationships between the microstructure and mechanical properties in a hot-rolled Si-Al-alloyed transformation-induced plasticity (TRIP)-aided steel was studied in a static tensile test. The morphological features of specimens deformed at the different temperatures were characterized by different microstructural techniques: optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). An increase in the deformation temperature from 20 to 200 °C resulted in the reduced effectiveness of the TRIP effect, due to the increasing mechanical stability of the γ phase. The gradual transformation of retained austenite into martensite expressed by a progressive increase in the work hardening exponent (n) led to a beneficial balance of strength, uniform elongation and total elongation. The best product of UTS × TEl = 17,805 MPa% showed the sample deformed at 20 °C with a peak n value amounting to 0.3.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Elevated Deformation Temperatures on Microstructural and Tensile Behavior of Si-Al Alloyed TRIP-Aided Steel

Kozłowska

Grajcar

2020

Materials

View full text Add to dashboard Cite

show abstract

“…Jo et al described that the occurrence of adiabatic shear bands (ASB) is less likely when the deformed material shows the DIMT effect [34]. However, the emergence of ASB is a well-known structure that forms in various metallic materials during deformation at high strain rates due to thermal-mechanical instability resulting from an abrupt temperature rise, followed by strong plastic flow [34]. Due to the high temperature rise, less α -martensite was formed in these regions and further investigations should look for the formation of ASB.…”

Section: Discussionmentioning

confidence: 99%

High Strain Rate and Stress-State-Dependent Martensite Transformation in AISI 304 at Low Temperatures

Fricke

Gerstein

Kotzbauer

et al. 2022

Metals

View full text Add to dashboard Cite

Deformation-induced martensitic transformation as the basis of a hardening process is dependent, among others, on the stress state. In applications such as cryogenic cutting, where a hardened martensitic subsurface can be produced in metastable austenitic steels, different stress states exist. Furthermore, cutting typically occurs at high strain rates greater than 103s−1. In order to gain a deeper insight into the behavior of a metastable austenitic steel (AISI 304) upon cryogenic cutting, the influence of high strain rates under different loading conditions was analyzed. It was observed that higher strain rates lead to a decrease in the α′-martensite content if exposed to tensile loads due to generated adiabatic heat. Furthermore, a lath-like α′-martensite was induced. Under shear stress, no suppression of α′-martensite formation by higher strain rates was found. A lath α′-martensite was formed, too. In the specimens that were subjected exclusively to compressive loading, almost no α′-martensite was present. The martensitic surface generated by cutting experiments showed deformation lines in which α′-martensite was formed in a wave-like shape. As for the shear specimens, more α′-martensite was formed with increasing strain rate, i.e., force. Additionally, magnetic etching proved to be an effective method to verify the transformation of ferromagnetic α′-martensite.

show abstract

“…Strain gages were attached to the bars to detect incident, transmitted, and reflected waves, which were recorded in an oscilloscope. Details of the SHPB testing were described in previous papers 28 – 31 . In a typical voltage vs. time curve of the open-cell Al foam specimen, the incident and reflected waves exhibited a nearly rectangular shape, while the transmitted wave was not observed because of the rapid closure of pores inside the foam specimen.…”

Section: Methodsmentioning

confidence: 99%

Energy-absorption analyses of honeycomb-structured Al-alloy and nylon sheets using modified split Hopkinson pressure bar

Kim,

Kim

et al. 2023

Sci Rep

Self Cite

View full text Add to dashboard Cite

Thin cylindrical honeycomb-structured aluminum alloy and mono-cast (MC) nylon were studied as superior energy-absorbing materials compared to metallic foams. Their energy-absorbing performance was assessed using a modified split Hopkinson pressure bar (SHPB). Key parameters included maximum impact acceleration (amax) and its reduction ratio (compared to the none-specimen case). The lowest amax reduction ratio was observed in bulk Al sheets without honeycomb cavities. As the cavity fraction increased up to 79% in honeycomb-structured Al specimens, the amax reduction ratio improved due to broadened stress–time curves with a shallow-plateau shape. This made high-cavity-fraction Al specimens preferable for higher-energy absorption and lighter-weight buffering materials. In nylon specimens, the amax reduction ratio increased until the fraction reached 52% due the softer and more deformable nature of the polymeric nylon. Thicker or rotated Al specimens also showed higher amax reduction ratios due to sufficient and continuous energy absorption. The modified SHPB demonstrated effective energy-buffering concepts and provided insightful amax interpretations, overcoming complexities in energy absorption analyses.

show abstract

Role of retained austenite on adiabatic shear band formation during high strain rate loading in high-strength bainitic steels

Cited by 17 publications

References 64 publications

Effect of Elevated Deformation Temperatures on Microstructural and Tensile Behavior of Si-Al Alloyed TRIP-Aided Steel

Effect of Elevated Deformation Temperatures on Microstructural and Tensile Behavior of Si-Al Alloyed TRIP-Aided Steel

High Strain Rate and Stress-State-Dependent Martensite Transformation in AISI 304 at Low Temperatures

Energy-absorption analyses of honeycomb-structured Al-alloy and nylon sheets using modified split Hopkinson pressure bar

Contact Info

Product

Resources

About