The Physical and Computer Modeling of Plastic Deformation of Low Carbon Steel in Semisolid State

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Marcin Hojny ◽  
Miroslaw Glowacki
Keyword(s):  
Computer Simulation ◽  
Low Carbon Steel ◽  
Mass Conservation ◽  
Analytical Form ◽  
Plastic Behavior ◽  
Volume Loss ◽  
Low Carbon ◽  
Compression Tests ◽  
Thermomechanical Model ◽  
Numerical Errors

This paper reports the results of theoretical and experimental work leading to the construction of a dedicated finite element method (FEM) system allowing the computer simulation of physical phenomena accompanying the steel sample testing at temperatures that are characteristic for integrated casting and rolling of steel processes, which was equipped with graphical, database oriented pre- and postprocessing. The kernel of the system is a numerical FEM solver based on a coupled thermomechanical model with changing density and mass conservation condition given in analytical form. The system was also equipped with an inverse analysis module having crucial significance for interpretation of results of compression tests at temperatures close to the solidus level. One of the advantages of the solution is the negligible volume loss of the deformation zone due to the analytical form of mass conservation conditions. This prevents FEM variational solution from unintentional specimen volume loss caused by numerical errors, which is inevitable in cases where the condition is written in its numerical form. It is very important for the computer simulation of deformation processes to be running at temperatures characteristic of the last stage of solidification. The still existing density change in mushy steel causes volume changes comparable to those caused by numerical errors. This paper reports work concerning the adaptation of the model to simulation of plastic behavior of axial-symmetrical steel samples subjected to compression at temperature levels higher than 1400°C. The emphasis is placed on the computer aided testing procedure leading to the determination of mechanical properties of steels at temperatures that are very close to the solidus line. Example results of computer simulation using the developed system are presented as well.

Hot Deformation Studies of a Low Carbon Steel Containing V

2013 ◽  
Vol 554-557 ◽  
pp. 1224-1231 ◽  
Author(s):  
Cecilia Poletti ◽  
Martina Dikovits ◽  
Javier Ruete
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Flow Instability ◽  
True Strain ◽  
Low Carbon Steel ◽  
Dynamic Effect ◽  
Rate Sensitivity ◽  
Low Carbon ◽  
Compression Tests ◽  
Deformation Parameters

Low alloyed steels produced by continuous casting are thermomechanically treated to achieve final high mechanical properties, meaning a good combination of strength and toughness. The hot deformation mechanisms of a micro-alloyed steel containing up to 0.1wt% of V is studied by means of hot compression tests using a Gleeble®3800 device. Austenitization of samples is carried out at 1150°C during 2 minutes followed by cooling to the deformation temperature at 1Ks-1in the range of 750 – 1150°C. The studied strain rate range is from 0.01 to 80 s-1and the total true strain achieved is of 0.7. In situ water quenching is applied after the deformation to freeze the microstructure and avoid any post dynamic effect. The Ar3temperature is determined by dilatometry experiments to be 725°C for the used cooling rate. The stress values obtained from the compression tests are evaluated at different strains to determine the strain rate sensitivity and flow instability maps and thus, to predict the formability of the material in the range of studied deformation parameters. These maps are correlated to the microstructure at specific deformation parameters.

scholarly journals Application of digital image correlation system for analysis of local plastic instabilities of perforated thin-walled bars

2018 ◽  
Vol 196 ◽  
pp. 01032 ◽  
Author(s):  
Andrzej Piotrowski ◽  
Marcin Gajewski ◽  
Cezary Ajdukiewicz
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Plastic Material ◽  
Low Carbon Steel ◽  
Image Correlation ◽  
Theoretical Point ◽  
Low Carbon ◽  
Compression Tests ◽  
Correlation System ◽  
Thin Walled

In the presented paper the local instabilities occurring in compression test of perforated thin-walled bars of low slenderness are observed using digital image correlation system ARAMIS. The tested samples slenderness is so low, that from theoretical point of view we are dealing with compression tests of some perforated shells. The samples are made from typical low carbon steel, which has to be treated as elasto-plastic material. Because of that, the final geometry of the sample (after unloading) is also analysed giving a good data for calibration of the theory of elasto-plasticity for large deformations. In analysed cases the total strain values are not exceptionally large, while local rotation (and permanent deformations) have significant values.

Study of the Plastic Deformation in Nanocrystalline and Ultrafine Iron and Carbon Steels

2008 ◽  
Vol 584-586 ◽  
pp. 617-622 ◽  
Author(s):  
Josep Antonio Benito ◽  
Robert Tejedor ◽  
Rodriguez Rodríguez-Baracaldo ◽  
Jose María Cabrera ◽  
Jose Manuel Prado
Keyword(s):  
Grain Size ◽  
Low Carbon Steel ◽  
High Strength ◽  
Carbon Steels ◽  
Low Carbon ◽  
Compression Tests ◽  
Consolidation Process ◽  
Heat Treated ◽  
Average Grain Size ◽  
Grain Size Distributions

Samples of nanostructured and ultrafine grained steels with carbon content ranging from 0.05 to 0.55%wt. have been obtained by a warm consolidation process from mechanically milled powders and subsequent heat treatments. In general, homogeneous grain size distributions were obtained except for the low-carbon steel in which a bimodal grain size distribution was observed when it was heat treated at high temperatures. The stress-strain response has been studied by means of compression tests. Nanostructured materials showed high strength but poor results in terms of ductility. In the low-ultrafine range (mean grain size between 100-500 nm) the three materials showed an increase in the ductility with strain softening. Finally, when the average grain size was close to 1 µm samples showed larger ductility and strain hardening.

scholarly journals Recovery and Recrystallization Behaviors of Ni–30 Mass Pct Fe Alloy During Uniaxial Cold and Hot Compression

2021 ◽  
Author(s):  
Itsuki Yamaguchi ◽  
Mitsuharu Yonemura
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Uniaxial Compression ◽  
Work Hardening ◽  
True Strain ◽  
Low Carbon Steel ◽  
Hot Compression ◽  
Low Carbon ◽  
Compression Tests

AbstractThe recovery and recrystallization behaviors of the high-temperature γ-phase of carbon steel during deformation strongly affect the mechanical properties of steel. However, it is difficult to evaluate such behaviors at a high temperature. This study proposes the deformation behavior of the high-temperature γ-phase of low-carbon steel based on the quantitative observation of dislocation density and vacancies in the Ni–30 mass pct Fe alloy. This alloy was used because its stacking fault energy (60 to 70 mJ m-2) is similar to that of low-carbon steel. Uniaxial compression tests were conducted at a strain rate of 10−3 s−1 and 1473 K (1200 °C) for dynamic recrystallization and at 293 K (20 °C) for work hardening. The compression process was interrupted at different strain values to systematically investigate microstructural changes. The changes in work hardening, recovery, and recrystallization behaviors were obtained from the true stress–true strain curves of the uniaxial compression tests. Further, the microstructure changes during cold and hot uniaxial compression were investigated from the viewpoint of lattice defects by X-ray diffraction, positron annihilation analysis, transmission electron microscopy, and electron backscatter diffraction to comprehend the work hardening, dynamic recovery (DRV), and dynamic recrystallization (DRX). This study helps understand the DRV, DRX, and work hardening behaviors in the γ-phase of the Ni–30 mass pct Fe alloy during cold and hot compression.

Controlling Mechanism of Ferrite Grain Size Generated through Large Strain Deformation of 0.15C Steel

2006 ◽  
Vol 503-504 ◽  
pp. 687-692
Author(s):  
S.V.S. Narayana Murty ◽  
Shiro Torizuka ◽  
Kotobu Nagai
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Large Strain ◽  
Low Carbon Steel ◽  
Temperature Deformation ◽  
Specific Reference ◽  
Low Carbon ◽  
Compression Tests ◽  
Controlling Mechanism ◽  
Ferrite Grain Size

During large strain deformation of materials, the width of the initial high angle grain boundaries approaches the order of mean diffusion distances encountered during elevated temperature deformation. Since the evolution of ultrafine grains is attributed to thermally activated processes, the role of interfaces in determining the grain size is significant. In order to investigate into this role, microstructure development in low carbon steel (0.15% C) subjected to large strain deformation was studied with specific reference to the controlling mechanism of ferrite grain size evolution. Plane strain compression tests have been conducted in the temperature range of 773-923K at strain rates of 0.01 s -1 and 1 s-1 and the specimens were deformed to 25% of the original thickness and the Microstructural evolution is studied. Based on the results obtained, diffusion along grain boundaries was found to be the mechanism controlling ferrite grain size in this material processed through large strain deformation.

Dynamic Recrystallization of Ferrite in a Low Carbon Steel with the (α+θ) Duplex Microstructures

2012 ◽  
Vol 715-716 ◽  
pp. 902-906
Author(s):  
Long Fei Li ◽  
Wang Yue Yang ◽  
Zu Qing Sun
Keyword(s):  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Low Carbon Steel ◽  
Hot Compression ◽  
Low Carbon ◽  
Compression Tests ◽  
Or Groups ◽  
Well Development ◽  
Average Size

Dynamic recrystallization (DRX) of ferrite in a low carbon steel with the (α+θ) duplex microstructures was investigated using hot compression tests in combination with SEM, TEM and EBSD, and the effect of the size of cementite particles was analyzed. The results indicated that during hot deformation of the low carbon steel DRX of ferrite took place and the increase in the average size of cementite particles was of benefit to DRX. The formation of DRX grains was attributed to particle stimulated nucleation (PSN), by the well development of the subgrain near cementite particles. At the beginning of hot deformation, DRX grains were mainly formed near cementite particles with the size of about 1μm or above. With the increase in the strain, such grains were also formed around pairs or groups of particles with the size of 0.5μm to 1μm.

An Experimental Investigation of the Influence of Strain-Rate and Temperature on the Flow Stress Properties of a Low Carbon Steel Using a Machining Test

1970 ◽  
Vol 185 (1) ◽  
pp. 741-754 ◽  
Author(s):  
M. G. Stevenson ◽  
P. L. B. Oxley
Keyword(s):  
Flow Stress ◽  
High Speed ◽  
Low Carbon Steel ◽  
Dynamic Strain ◽  
Low Carbon ◽  
Compression Tests ◽  
Dynamic Strain Ageing ◽  
Tension And Compression ◽  
Machining Test ◽  
Strain Equation

Results obtained from machining and conventional slow-speed compression tests are used to calculate the constants σ1 and n in the empirical stress/strain equation σ = σ1***enover a range of strain-rates (10-3to 2·8 times 104/s) and temperatures (room temperature to 200°C) for a low carbon, free machining steel. The results are consistent with those obtained for a similar material using high-speed tension tests. Some results showing the influence of higher temperatures (up to 800°C) on the flow stress are also obtained from the machining tests by considering the flow along the tool-chip interface. These results show a dynamic strain-ageing effect similar to that found in high-speed tension and compression tests on similar materials.

Plastic Behavior of Metals at Large Strains: Experimental Studies Involving Simple Shear

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
E. F. Rauch
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Simple Shear ◽  
Equal Channel Angular Extrusion ◽  
Experimental Studies ◽  
Low Carbon Steel ◽  
Stage Iv ◽  
Large Strains ◽  
Plastic Behavior ◽  
Low Carbon

Two experimental devices that promote simple shear are used to investigate the plastic behavior of metals under very large strains. First, researches on the anisotropic behaviors of sheets of metals performed with the help of the planar simple shear test are reviewed. In particular, it is shown that, with this device, stage IV may be reached and analyzed on polycrystals as well as on single crystals. The second part is devoted to equal channel angular extrusion, which is known to promote grain refinement after several passes. A direct comparison of the crystallographic textures measured on sheared and on extruded samples confirms that the extrusion promotes massively simple shear. Besides, the grain refinement is measured with a dedicated transmission electron microscopy (TEM) attachment. It is shown that the grain size decreases regularly for a low carbon steel as well as for copper, down to around 1 μm. It is argued that the sustained hardening in stage IV is a mechanical signature of the grain size decrease. The trend is interpreted and reproduced quantitatively with the help of a simple modeling approach.

Dynamic Recrystallization of Ferrite in Low Carbon Steels

2007 ◽  
Vol 558-559 ◽  
pp. 617-622 ◽  
Author(s):  
Zu Qing Sun ◽  
Long Fei Li ◽  
Wang Yue Yang
Keyword(s):  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Compression Tests ◽  
Hollomon Parameter ◽  
Low Carbon Steels ◽  
Continuous Dynamic Recrystallization ◽  
Continuous Dynamic

Dynamic recrystallization(DRX) of ferrite in low carbon steels was investigated by hot compression tests at temperatures of 550 to 700oC at strain rates of 0.001 to 10s-1. The results indicate that DRX of ferrite can occur in low carbon steels and lead to grain refinement. With increasing Zener-Hollomon parameter Z, its mechanism changes from discontinuous dynamic recrystallization to continuous dynamic recrystallization, the turning point is approximately at Z=1×1016s-1 for a low carbon steel with 0.171wt% C. The results also indicate that changing the minor constituents of the low carbon steel from pearlite colonies to fine cementite particles has an effect on promoting DRX of ferrite, and the increase of Mn content and the presence of tiny Nb precipitates have opposite effects respectively. However, all these changes are of benefit to the refinement of recrystallized grains.

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