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.

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.

Texture Developments during Ferrite Refinement through Deformation-Enhanced Ferrite Transformation and Dynamic Recrystallization in Low Carbon Steel

2005 ◽  
Vol 475-479 ◽  
pp. 165-168 ◽  
Author(s):  
Ping Yang ◽  
Wang Yue Yang ◽  
Zu Qing Sun
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Recrystallization Texture ◽  
Low Carbon Steel ◽  
Deformation Texture ◽  
Low Carbon ◽  
Ferrite Transformation ◽  
Transformation Texture ◽  
Ferrite Grain Size

Texture evolutions are determined by XRD and EBSD techniques during ferrite refinement through deformation-enhanced ferrite transformation (DEFT) and dynamic recrystallization (DREX). Evidences of transformation texture, deformation texture and recrystallization texture during DEFT are provided and compared with the texture during DREX. The influence of pass-interval during DEFT on texture is illustrated. Results are discussed in terms of the influences of ferrite grain size and deforming temperature.

Microstructure and Mechanical Properties of Nb Alloyed Steel Processed by Hot Equal Channel Angular Extrusion

2016 ◽  
Vol 879 ◽  
pp. 2528-2531
Author(s):  
Akira Yanagida ◽  
Ryo Aoki ◽  
Masataka Kobayashi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Equal Channel Angular Extrusion ◽  
Low Carbon Steel ◽  
Total Elongation ◽  
Low Carbon ◽  
Angular Extrusion ◽  
Ferrite Grain Size

A Nb alloyed low carbon steel was processed by hot equal channel angular extrusion (ECAE) and following transformation. The workpieces were heated up to the 960°C in the furnace for 10 min within the container block. Before extrusion, the die was preheated to 400oC. The workpiece was cooled in the die after ECAE process. 1 pass and 2 pass via route C were conducted at a speed of 32mm/s, the inter-pass time is about 2 sec. The sample of average ferrite grain size of about 2μm, a tensile strength of 800MPa, a total elongation about 20% is produced after 2 pass ECAE processed and subsequent cooling.

scholarly journals Prediction of Ferrite Grain Size after Warm Deformation of Low Carbon Steel.

1996 ◽  
Vol 36 (10) ◽  
pp. 1279-1285 ◽  
Author(s):  
A. Schmickl ◽  
D. Yu ◽  
C. Killmore ◽  
D. Langley ◽  
T. Chandra
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Warm Deformation ◽  
Ferrite Grain Size

Intercritical Annealing Behaviour of an Ultrafine Grained C-Mn Steel Obtained by Hot Torsion Deformation

2007 ◽  
Vol 550 ◽  
pp. 471-476
Author(s):  
G. Azevedo ◽  
Ronaldo Barbosa ◽  
Elena V. Pereloma ◽  
Dagoberto Brandão Santos
Keyword(s):  
Grain Size ◽  
Intercritical Annealing ◽  
True Strain ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Homogeneous Microstructure ◽  
Ultrafine Grained ◽  
Hot Torsion ◽  
Ferrite Grain Size ◽  
Torsion Deformation

Several studies concerning ferrite grain refinement have been developed in recent the last years due to the recognised influence of such microstructures on steels properties. This work was focused on the evaluation of the microstructure and mechanical properties of an ultrafine grained CMn steel obtained by hot torsion deformation and intercritical annealing. After 5 min soaking at 900 and 1200°C, the samples of low carbon steel were quenched and then reheated. Hot torsion deformation was conducted at temperatures of 700 or 740°C. The torsion schedule consisted of 7 isothermal passes leading to a total true strain of ≈1 and generating an ultrafine and inhomogeneous microstructure with grain sizes of the order of 1-m, formed by strain-induced dynamic transformation (SIDT). The samples were heated up to 800oC and held for 1, 2 and 3 h. A more homogeneous microstructure and ferrite grain size were obtained after annealing The microhardness tests showed the reduction in hardness with the increase in annealing time. They also highlighted the effects of the ferrite grain size and the volume fractions of the microstructure constituents.

Relationship between Grain Boundary Diffusion and Ferrite Grain Size Formed through Dynamic Recrystallization during Large Strain Deformation

2007 ◽  
Vol 558-559 ◽  
pp. 595-600 ◽  
Author(s):  
Shiro Torizuka ◽  
S.V.S. Narayana Murty
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Boundary Diffusion ◽  
Large Strain ◽  
Grain Boundary Diffusion ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Low Carbon ◽  
Hollomon Parameter ◽  
Ferrite Grain Size

During large strain deformation of materials, the high angle grain boundary spacing approaches the order of mean thermal diffusion distances for given deformation conditions. Based on the results of microstructural and grain size analysis in low carbon steel subjected to large strain-high Z deformation, the evolved ferrite grain size was found to be controlled by the Zener-Hollomon parameter and grain boundary diffusion was found to be the controlling mechanism.

scholarly journals Strain Hardening of Low-Carbon Steel in the Area of Jerky Flow

2021 ◽  
pp. 65-75
Author(s):  
І. О Vakulenko ◽  
D. M Bolotova ◽  
S. V Proidak ◽  
B Kurt ◽  
A. E Erdogdu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Carbon Steel ◽  
Strain Hardening ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Cold Plastic Deformation ◽  
Low Carbon ◽  
Jerky Flow ◽  
Ferrite Grain Size

Purpose. The aim of this work is to assess the effect of ferrite grain size of low-carbon steel on the development of strain hardening processes in the area of nucleation and propagation of deformation bands. Methodology. Low-carbon steels with a carbon content of 0.06–0.1% C in various structural states were used as the material for study. The sample for the study was a wire with a diameter of 1mm. The structural studies of the metal were carried out using an Epiquant light microscope. Ferrite grain size was determined using quantitative metallographic techniques. Different ferrite grain size was obtained as a result of combination of thermal and termo mechanical treatment. Vary by heating temperature and the cooling rate, using cold plastic deformation and subsequent annealing, made it possible to change the ferrite grain size at the level of two orders of magnitude. Deformation curves were obtained during stretching the samples on the Instron testing machine. Findings. Based on the analysis of stretching curves of low-carbon steels with different ferrite grain sizes, it has been established that the initiation and propagation of plastic deformation in the jerky flow area is accompanied by the development of strain hardening processes. The study of the nature of increase at dislocation density depending on ferrite grain size of low-carbon steel, starting from the moment of initiation of plastic deformation, confirmed the existence of relationship between the development of strain hardening at the area of jerky flow and the area of parabolic hardening curve. Originality. One of the reasons for decrease in Luders deformation with an increase of ferrite grain size of low-carbon steel is an increase in strain hardening indicator, which accelerates decomposition of uniform dislocations distribution in the front of deformation band. The flow stress during initiation of plastic deformation is determined by the additive contribution from the frictional stress of the crystal lattices, the state of ferrite grain boundaries, and the density of mobile dislocations. It was found that the size of dislocation cell increases in proportion to the diameter of ferrite grain, which facilitates the development of dislocation annihilation during plastic deformation. Practical value. Explanation of qualitative dependence of the influence of ferrite grain size of a low-carbon steel on the strain hardening degree and the magnitude of Luders deformation will make it possible to determine the optimal structural state of steels subjected to cold plastic deformation.

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