Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

Alturk, Rakan; Hector, Louis G.; Enloe, Charles M.; Abu-Farha, Fadi; Brown, Tyson

doi:10.1007/s11837-018-2830-3

Cited by 35 publications

(8 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[37] Typical ranges of strain rates associated with sheet forming and vehicle crashes are approximately 10 À1 to 10 s À1 and 10 2 to 10 3 s À1 , respectively. [37][38][39] At rates in excess of 10 À2 s À1 , deformation-induced heating is significant in the workpiece, [40][41][42][43][44] which is problematic because the driving force for DIMT is intrinsically responsive to temperature. [45][46][47][48][49][50][51] Furthermore, the number of shear band intersections increases significantly as strain rates are increased from quasi-static to dynamic; this is important because shear band intersections are considered to be the primary sites for martensite nucleation during DIMT.…”

Section: Introductionmentioning

confidence: 99%

Strain Rate Dependent Ductility and Strain Hardening in Q&P Steels

Finfrock

Thrun

Bhattacharya

et al. 2021

Metall Mater Trans A

View full text Add to dashboard Cite

Due to their high strength, formability and affordable cost, quenched and partitioned (Q&P) steels have shown the potential to reduce the mass of vehicles, thereby decreasing fuel consumption during service. Furthermore, because a lower mass of steel is used in each vehicle, energy consumption associated with the steelmaking process is also reduced. Q&P steels utilize the deformation-induced martensitic transformation (DIMT) of metastable retained austenite to enhance ductility and strain hardening. Accordingly, improvement of mechanical performance is contingent on the ability to precisely control the chemical and mechanical stability of austenite. Considering the multitude of factors that influence austenite stability, optimizing microstructures to delay necking or fracture is challenging, particularly as temperature and strain rate increase. Tensile tests of an intercritically annealed C-Mn-Si Q&P steel were performed over a range of strain rates (10 À4 to 10 À1 s À1 ) to evaluate effects on the DIMT and sheet tensile properties. As strain rates increased from 10 À4 to 10 À1 s À1 , the uniform elongation decreased from approximately 19 to 14 pct. This reduction in uniform elongation is associated with a decrease in the strain hardening exponent near the onset of strain localization. Based on experimental data from this study and review of previous research, it is postulated that the strengthening contribution of DIMT is controlled by competing effects of: (i) a decreasing chemical driving force for DIMT caused by deformation-induced heat accumulation at higher strain rates and (ii) an increasing number of martensite nucleation sites. This suggests that tailoring austenite stability for specific deformation conditions could enable further optimization of formability and vehicle crash behavior.

show abstract

Section: Introductionmentioning

confidence: 99%

Strain Rate Dependent Ductility and Strain Hardening in Q&P Steels

Finfrock

Thrun

Bhattacharya

et al. 2021

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…Medium-Mn steels (~3–11 wt.% Mn) are a new category of advanced high strength steels (AHSS) that have attracted research interest worldwide in recent years [1,2,3,4,5]. These steels have fine microstructures and contain a large fraction of metastable retained austenite, thus exhibiting excellent strength and elongation.…”

Section: Introductionmentioning

confidence: 99%

“…In the deformation process, the metastable austenite exhibits a transformation-induced plasticity (TRIP) effect or a twinning-induced plasticity (TWIP) effect, which gives the medium-Mn steel excellent plasticity without sacrificing strength. This allows the material to meet the processing requirement for automobile parts with complex structures [5,6,7,8]. Therefore, the amount of retained austenitein medium-Mn steels determine show extensive is the TRIP effect; that is, the transformation of retained austenite into martensite during deformation increases the strength and ductility of steel simultaneously [1,2,3,4,5,6,7,8].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Mechanical Properties of Hot- Rolled and Cold-Rolled Medium-Mn TRIP Steels

et al. 2018

View full text Add to dashboard Cite

This study investigated the microstructure and mechanical properties of hot-rolled and cold-rolled medium-Mn transformation-induced plasticity (TRIP) steel. The experimental steel, processed by quenching and tempering (Q & T) heat treatment, exhibited excellent mechanical properties for hot-rolled and Q & T steels (strength of 1050–1130 MPa and ductility of 16–34%), as well as for cold-rolled and Q & T steels (strength of 878–1373 MPa and ductility of 18–40%). The mechanical properties obtained after isothermal holding at 775 °C for one hour for cold-rolled/Q & T steel were superior to that of hot-rolled/Q & T steel. Excellent mechanical properties were attributed to the large amount of retained austenite, which produced a discontinuous TRIP effect. Additionally, the differences in mechanical properties correlated with the morphology, stability and content of retained austenite. The cold-rolled sample, quenched from 650 °C (CR 650°C) had extensive TRIP effects in the middle and late stages of the deformation, leading to better mechanical properties. The fracture modes of the hot-rolled sample, quenched from 650 °C, and the cold-rolled sample quenched from 650 °C, were ductile fractures, resulting in excellent ductility.

show abstract

“…Besides the deformation temperature, some previous studies [31,32] revealed that the strain rate and the deformation mode would also affect the macroscopic behaviors (e.g., the band shape and the band propagation behaviors) and the microscopic behaviors (e.g., martensitic transformation kinetics) in medium Mn steels. Although our microscopic mechanistic framework is proposed to explain the effect brought by the different deformation temperatures, we believe that it could also be applied to interpret these behaviors at different strain rates, because the effect brought by higher strain rates is similar to that brought by lower deformation temperatures and vice versa.…”

Section: Conclusion and Summary Remarksmentioning

confidence: 99%

Temperature-Dependent Macroscopic Mechanical Behaviors and Their Microscopic Explanations in a Medium Mn Steel

Liu

et al. 2020

Metall Mater Trans A

View full text Add to dashboard Cite

Plastic instability (e.g., Lü ders band and PLC band) is a phenomenon frequently observed in cold-rolled medium Mn steels. In this study, through a number of quasi-static uniaxial tensile tests with digital image correlation (DIC) measurement of the strain rate field, we found the medium Mn steel (Fe-0.14C-7.14Mn-0.23Si wt. pct with approximately 33 vol pct of retained austenite and 67 vol pct of ferrite) exhibited distinct competition/coordination between the Lu¨ders band and the PLC band at different deformation temperatures: (1) at 25°C and 55°C, a Lu¨ders band was followed by several PLC bands; (2) at 100°C, fracture occurred right after the Lu¨ders band formation, without the presence of a PLC band; (3) at 250°C, only PLC bands were observed. We propose that these macroscopic behaviors can be explained by the temperature-dependent conditions for the formation/appearance and propagation of Lu¨ders bands and PLC bands. The propagation of Lu¨ders bands becomes difficult when the temperature increases as less hardening is provided by martensitic transformation. In contrast, the appearance and propagation of PLC bands become easier when the temperature increases and/or the plastic strain becomes large (16.5 and 18.9 pct in this material at the deformation temperatures of 25°C and 55°C, respectively), as the difference in the average velocities of solute atom diffusion and dislocation gliding is reduced. Either condition for Lu¨ders bands or for PLC bands will be satisfied at different deformation temperatures or plastic strains, thus leading to the competition/coordination between them.

show abstract

Strain Rate Effect on Tensile Flow Behavior and Anisotropy of a Medium-Manganese TRIP Steel

Cited by 35 publications

References 43 publications

Strain Rate Dependent Ductility and Strain Hardening in Q&P Steels

Strain Rate Dependent Ductility and Strain Hardening in Q&P Steels

Microstructure and Mechanical Properties of Hot- Rolled and Cold-Rolled Medium-Mn TRIP Steels

Temperature-Dependent Macroscopic Mechanical Behaviors and Their Microscopic Explanations in a Medium Mn Steel

Contact Info

Product

Resources

About