scholarly journals Effect of Deformation Temperature on the Portevin-Le Chatelier Effect in Medium-Mn Steel

Metals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Barbara Grzegorczyk ◽  
Aleksandra Kozłowska ◽  
Mateusz Morawiec ◽  
Rafał Muszyński ◽  
Adam Grajcar
Keyword(s):  
Deformation Temperature ◽  
Tensile Deformation ◽  
Plastic Instability ◽  
Manganese Steel ◽  
Experimental Investigations ◽  
Medium Manganese Steel ◽  
Medium Mn Steel ◽  
Lower Strain ◽  
Chatelier Effect ◽  
Hot Rolled

Experimental investigations of the plastic instability phenomenon in a hot-rolled medium manganese steel were performed. The effects of tensile deformation in a temperature range of 20–140°C on the microstructure, mechanical properties, and flow stress serrations were analyzed. The Portevin–Le Chatelier (PLC) phenomenon was observed for the specimens deformed at 60 °C, 100 °C, and 140 °C. It was found that the deformation temperature substantially affects the type and intensity of serrations. The type of serration was changed at different deformation temperatures. The phenomenon was not observed at room temperature. The plastic instability occurring for the steel deformed at 60 °C was detected for lower strain levels than for the specimens deformed at 100 °C and 140 °C. The increase of the deformation temperature to 100 °C and 140 °C results in shifting the PLC effect to a post uniform deformation range. The complex issues related to the interaction of work hardening, the transformation induced plasticity (TRIP) effect, and the PLC effect stimulated by the deformation temperature were addressed.

scholarly journals Discontinuous strain-induced martensite transformation related to the Portevin-Le Chatelier effect in a medium manganese steel

2017 ◽  
Vol 133 ◽  
pp. 9-13 ◽  
Author(s):  
Binhan Sun ◽  
Nicolas Vanderesse ◽  
Fateh Fazeli ◽  
Colin Scott ◽  
Jianqiang Chen ◽  
...  
Keyword(s):  
Martensite Transformation ◽  
Manganese Steel ◽  
Medium Manganese Steel ◽  
Strain Induced Martensite ◽  
Chatelier Effect

Microstructure Evolution and Mechanical Properties of 67GPa•% Grade Medium Manganese Steel

2021 ◽  
Vol 1035 ◽  
pp. 404-409
Author(s):  
Zhe Rui Zhang ◽  
Ren Bo Song ◽  
Nai Peng Zhou ◽  
Wei Feng Huo
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Annealing Temperature ◽  
High Strength ◽  
Total Elongation ◽  
Manganese Steel ◽  
Experimental Steel ◽  
Medium Manganese Steel ◽  
Hot Rolled ◽  
Hot Rolled Steel

In this study, a new Fe-6Mn-4Al-0.4C high strength medium manganese hot rolled steel sheet was designed. The influence mechanism of the intercritical annealing (IA) temperature on microstructure evolution and mechanical properties of experimental steel were studied by SEM and XRD. The experimental steel was held for 30 minutes at 640°C, 680°C, 720°C, 760°C, 800°C, respectively. When the annealing temperature was 640°C, cementite particles precipitated between the austenite and ferrite phase boundary. As the annealing temperature increased, the cementite gradually dissolved and disappeared, the fraction of lamellar austenite increased significantly. When the annealing temperature is 800°C, the coarse equiaxed austenite and ferrite appeared. The yield strength (YS) decreased, the product of strength and elongation (PSE) and total elongation (TE) both increased first and then decreased, while the ultimate tensile strength (UTS) showed the opposite trend. The experimental steel exhibited excellent comprehensive mechanical properties after held at 760°C for 30 min. The UTS was 870 MPa, the YS was 703 MPa, and the TE was 77 %, the PSE was 67 GPa·%.

scholarly journals Propagating bands of plastic deformation in a metal alloy as critical avalanches

2020 ◽  
Vol 6 (41) ◽  
pp. eabc7350
Author(s):  
Tero Mäkinen ◽  
Pasi Karppinen ◽  
Markus Ovaska ◽  
Lasse Laurson ◽  
Mikko J. Alava
Keyword(s):  
Plastic Deformation ◽  
Tensile Deformation ◽  
Mean Field ◽  
Plastic Instability ◽  
Barkhausen Effect ◽  
Mean Field Model ◽  
Velocity Signal ◽  
Large Fluctuations ◽  
Resolution Imaging ◽  
Chatelier Effect

The plastic deformation of metal alloys localizes in the Portevin–Le Chatelier effect in bands of different types, including propagating, or type “A” bands, usually characterized by their width and a typical propagation velocity. This plastic instability arises from collective dynamics of dislocations interacting with mobile solute atoms, but the resulting sensitivity to the strain rate lacks fundamental understanding. Here, we show, by using high-resolution imaging in tensile deformation experiments of an aluminum alloy, that the band velocities exhibit large fluctuations. Each band produces a velocity signal reminiscent of crackling noise bursts observed in numerous driven avalanching systems from propagating cracks in fracture to the Barkhausen effect in ferromagnets. The statistical features of these velocity bursts including their average shapes and size distributions obey predictions of a simple mean-field model of critical avalanche dynamics. Our results thus reveal a previously unknown paradigm of criticality in the localization of deformation.

Correlation between cementite precipitation and Portevin-Le Chatelier effect in a hot-rolled medium Mn steel

2020 ◽  
Vol 258 ◽  
pp. 126796 ◽  
Author(s):  
Yongjin Wang ◽  
Zetian Ma ◽  
Renbo Song ◽  
Shuai Zhao ◽  
Zherui Zhang ◽  
...  
Keyword(s):  
Medium Mn Steel ◽  
Chatelier Effect ◽  
Hot Rolled ◽  
Mn Steel

Understanding Hot vs. Cold Rolled Medium Manganese Steel Deformation Behavior Using In Situ Microscopic Digital Image Correlation

2018 ◽  
Vol 941 ◽  
pp. 198-205 ◽  
Author(s):  
Aniruddha Dutta ◽  
Dirk Ponge ◽  
Stefanie Sandlöbes ◽  
Dierk Raabe
Keyword(s):  
Image Correlation ◽  
Manganese Steel ◽  
Tempered Martensite ◽  
Spatial Alignment ◽  
Medium Manganese Steel ◽  
Reverted Austenite ◽  
Cold Rolled ◽  
Fresh Martensite ◽  
Hot Rolled ◽  
Continuous Yielding

We address the differences in yield stresses between hot and cold rolled medium manganese steel showing continuous yielding. Continuous yielding in both, the hot and cold rolled samples were resulting from reverted austenite islands plastically deforming first and less strain in the tempered martensite matrix. At higher global strains, strain was taken up not only by the reverted austenite, but also by tempered martensite and fresh martensite formed from the austenite through martensitic phase transformation during deformation. Strain localization was also observed in the hot rolled samples. This localization is caused by cumulative deformation of colonies of lamellar reverted austenite islands. It is interpreted in terms of the spatial alignment of austenite colonies to the loading direction in addition to the crystallographic orientation.

Impact and Rolling Abrasive Wear Behavior and Hardening Mechanism for Hot-Rolled Medium-Manganese Steel

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Jian Wang ◽  
Qingliang Wang ◽  
Xiao Zhang ◽  
Dekun Zhang
Keyword(s):  
Wear Resistance ◽  
Martensitic Transformation ◽  
Work Hardening ◽  
Wear Behavior ◽  
Manganese Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
Medium Manganese Steel ◽  
Dislocation Strengthening ◽  
Hot Rolled

The coupled impact and rolling wear behavior of the medium-manganese austenitic steel (Mn8) were studied by comparison with the traditional Hadfield (Mn13) steel. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), and transmission electron microscope (TEM) were used to analyze the wear and hardening mechanisms. The experimental results show that the impact and rolling wear resistance of hot-rolled medium-manganese steel (Mn8) is better than that of high-manganese steel (Mn13) under conditions of low-impact load. The better work hardening sensitivity effectively improves the wear resistance of medium-manganese steel. Not only the coefficient of friction is low, but the mass loss and wear rate of the wear are lower than that of high-manganese steel. After impact and rolling wear, a hardened layer with a thickness of about 600 μm is formed on the wear surface. The highest microhardness of the subsurface layer for Mn8 is about 594 HV and the corresponding Rockwell hardness is about 55 HRC, showing the remarkable work hardening effect. The wear-resistant strengthening mechanism of medium-manganese steel is compound strengthening, including the deformation-induced martensitic transformation, dislocation strengthening, and twin strengthening. In initial stages of impact and rolling abrasion, dislocation strengthening plays a major role. When the deformation reaches a certain extent, the deformation-induced martensitic transformation and twinning strengthening begin to play a leading role.

Strain Rate Dependent Mechanical Stability of Retained Austenite in Hot-Rolled Medium-Mn Sheet Steels

2021 ◽  
Vol 1016 ◽  
pp. 946-951
Author(s):  
Mateusz Morawiec ◽  
Adam Grajcar
Keyword(s):  
Strain Rate ◽  
Mechanical Stability ◽  
Total Elongation ◽  
Manganese Steel ◽  
Strain Rates ◽  
Sheet Steels ◽  
Rate Dependent ◽  
Medium Manganese Steel ◽  
Dynamic Tensile Test ◽  
Hot Rolled

The paper presents microstructural and mechanical results of medium manganese steel deformed under high strain rates. The rotary hammer tests at strain rates of 250, 500 and 1000 s-1 were applied. Mechanical properties under dynamic tensile loads were determined. According to the obtained results, when strain rate increased the yield point of the steel increased. An opposite trend was present regarding total elongation. In case of tensile strength, its level is similar for all analyzed deformation rates. The microstructure of the steel after the dynamic tensile test is composed of bainite, martensite and martensitic-austenitic islands. The strain-induced martensitic transformation was identified in microscopic investigations.

scholarly journals Analysis of Plastic Deformation Instabilities at Elevated Temperatures in Hot-Rolled Medium-Mn Steel

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4184 ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Barbara Grzegorczyk ◽  
Marcin Staszuk ◽  
Paweł M. Nuckowski ◽  
Adam Grajcar
Keyword(s):  
Plastic Deformation ◽  
Deformation Temperature ◽  
Elevated Temperatures ◽  
Thermomechanical Processing ◽  
Uniform Elongation ◽  
High Strength ◽  
Tensile Tests ◽  
Manganese Steel ◽  
Serrated Flow ◽  
Hot Rolled

The study addressed the microstructure and mechanical properties of hot-rolled advanced high-strength medium manganese steel. Some of the curves that were obtained in static tensile tests at deformation temperatures of 20–200 °C showed the occurrence of the heterogeneous plastic deformation phenomenon, called the Portevin-Le Chatelier (PLC) effect. The deformation temperature significantly influenced a serration character. The correlations between the deformation temperature, serration range, microstructural features, and fracture behavior were investigated. The curves showed no Lüders elongation as a result of the thermomechanical processing applied. The serrated flow phenomenon was observed at 60 and 140 °C. The serration type was different and the most enhanced at 140 °C, where the PLC effect was present in both uniform and post-uniform elongation ranges. The disappearance of serrations at 200 °C was related to the increased diffusion intensity.

Microstructure and Mechanical Properties of an Ultrafine Grained Medium-Mn Steel

2018 ◽  
Vol 385 ◽  
pp. 308-313 ◽  
Author(s):  
Vladimir Torganchuk ◽  
Dmitri A. Molodov ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Total Elongation ◽  
Manganese Steel ◽  
Two Phase ◽  
Microstructure And Mechanical Properties ◽  
Ultrafine Grained ◽  
Medium Manganese Steel ◽  
Medium Mn Steel ◽  
Mn Steel

The effect of cold working followed by annealing on the development of ultrafine grained microstructure and mechanical properties of an Fe-12%Mn-0.6%C-1.5%Al medium-manganese steel was studied. The steel was cold rolled with intermediate annealings and then annealed at 873 K or 923 K for 30 min. The yield strength and total elongation of the Fe-12Mn-0.6C-1.5Al steel after cold rolling were 1200 MPa and 14%, respectively. The heat treatments resulted in the formation of two phase (austenite-ferrite) ultrafine grained microstructures with average grain sizes of 0.9 to 1.2 μm, depending on the annealing temperature. The annealed ultrafine grained steel samples exhibit the yield strength in the range of 800-950 MPa, the ultimate tensile strength in the range of 1150-1200 MPa, and total elongation of 12% to 19%.

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