Orientation Selection in ULC Steel during Thermally Activated Phenomena Induced by Cold Deformation

2007 ◽  
Vol 550 ◽  
pp. 491-496
Author(s):  
Kim Verbeken ◽  
Leo Kestens
Keyword(s):  
Cold Rolling ◽  
Cold Deformation ◽  
Secondary Recrystallization ◽  
Local Strain ◽  
Primary Recrystallization ◽  
Low Carbon ◽  
Orientation Selection ◽  
Thermally Activated ◽  
Open Questions ◽  
Cold Rolled

The scope of this work was to study the physical metallurgical behaviour of the microstructure and the texture of ultra low carbon (ULC) steel during cold rolling and subsequent thermally activated phenomena. It was the intention to contribute to the scientific search for the answer to many open questions raised in recent literature. The powerful tool of quantitative texture analysis, together with modern measurement equipment was used for this purpose. At first, a ULC steel was cold rolled to two different rolling reductions and the local strain heterogeneities after the cold rolling were studied. Secondly, crystallographic orientation selection during primary recrystallization was considered both for cold rolled ULC steel and for a Fe-2.8%Si single crystal. The latter was a re-evaluation of the historic growth selection experiment by Ibe and Lücke. Finally, secondary recrystallization in ULC steels was evaluated in terms of oriented nucleation and selective growth.

Recrystallization and Grain Growth Behavior of few Low Carbon Steels after Severe Cold Rolling and Annealing

2013 ◽  
Vol 753 ◽  
pp. 201-206
Author(s):  
Ranjit K. Ray ◽  
Rajib Saha
Keyword(s):  
Cold Rolling ◽  
Grain Growth ◽  
Systematic Investigation ◽  
Carbon Steels ◽  
Growth Behavior ◽  
Interstitial Free ◽  
Low Carbon ◽  
Cold Rolled ◽  
Grain Growth Behavior ◽  
Very High

Less attention has been paid to study the recrystallization and grain growth behavior of severe plastically deformed (SPD) metals specially steels that are deformed to very high strain by conventional rolling method. Present work has been focused on systematic investigation of recrystallization and grain growth behavior of a Aluminium Killed (AK), an Interstitial Free (IF) and an Interstitial Free High Strength (IFHS) steels that were subjected to very high levels of strain (ԑeqv= 4.51) by cold rolling. The cold rolled steels show fine lamellar structure with very strong texture consists of both γ and α fibre. All the steels show formation of ultrafine grains and dramatic rise in the intensity of α fibre component in the early stages of annealing. However, progress of annealing for longer time leads to an increase in the mean grain size as well as γ fibre intensity. The results also indicate that the heavily cold rolled material exhibit selective growth of specific texture components.It appears that microstructure and texture is closely related to the observed phenomenon.

Oriented Nucleation and Selective Growth during Secondary Recrystallization in Ultra Low Carbon Steels

2004 ◽  
Vol 467-470 ◽  
pp. 941-948 ◽  
Author(s):  
Kim Verbeken ◽  
Leo Kestens
Keyword(s):  
Grain Growth ◽  
Texture Evolution ◽  
Secondary Recrystallization ◽  
Low Carbon Steel ◽  
Primary Recrystallization ◽  
Carbon Steels ◽  
Abnormal Grain Growth ◽  
Selective Growth ◽  
Low Carbon ◽  
Ultra Low Carbon Steel

After primary recrystallization, on further annealing, abnormal grain growth occurred in ultra low carbon steel. Texture evolution was studied by comparing the orientations after complete secondary recrystallization, with on one hand the nuclei for abnormal grain growth and on the other hand the selective growth products of the primary recrystallized matrix. The influence of both mechanisms could be identified in the final texture.

scholarly journals Effect of Carbide Size, Cold Reduction and Heating Rate in Annealing on Deep-Drawability of Low-Carbon, Capped Cold-Rolled Steel Sheet

1978 ◽  
Vol 3 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Kazuo Matsudo ◽  
Takayoshi Shimomura ◽  
Osamu Nozoe
Keyword(s):  
Cold Rolling ◽  
Heating Rate ◽  
Cold Reduction ◽  
Recrystallization Temperature ◽  
Rolled Steel ◽  
Low Carbon ◽  
Initial State ◽  
Cold Rolled Steel ◽  
Carbide Size ◽  
Cold Rolled

The effects of carbide size prior to cold rolling, cold reduction and heating rate in annealing on r¯-value, and texture of cold-rolled steel sheets were investigated. The main results obtained were as follows: (1) When the carbide size prior to cold rolling is large, r¯-value can be improved with a faster heating rate in annealing. (2) Moreover, the cold reduction of peak r¯-value shifts to the higher cold reduction side, and r¯-value tends to increase with cold reduction up to 90%. These phenomena are thought to be based on the delay in dissolution of carbide at the initial state of recrystallization, the change in recrystallization temperature and the preferred nucleation.

Effect of Dislocation Distribution on the Yielding of Highly Dislocated Iron

2007 ◽  
Vol 539-543 ◽  
pp. 228-233 ◽  
Author(s):  
Setsuo Takaki ◽  
Y. Fujimura ◽  
Koichi Nakashima ◽  
Toshihiro Tsuchiyama
Keyword(s):  
Dislocation Density ◽  
Cold Rolling ◽  
Microstructural Change ◽  
Low Carbon ◽  
Proportional Limit ◽  
Proof Stress ◽  
Cold Rolled ◽  
Cold Worked ◽  
Carbon Martensite ◽  
Distributed Dislocations

Yield strength of highly dislocated metals is known to be directly proportional to the square root of dislocation density (ρ), so called Bailey-Hirsch relationship. In general, the microstructure of heavily cold worked iron is characterized by cellar tangled dislocations. On the other hand, the dislocation substructure of martensite is characterized by randomly distributed dislocations although it has almost same or higher dislocation density in comparison with heavily cold worked iron. In this paper, yielding behavior of ultra low carbon martensite (Fe-18%Ni alloy) was discussed in connection with microstructural change during cold working. Originally, the elastic proportional limit and 0.2% proof stress is low in as-quenched martensite in spite of its high dislocation density. Small amount of cold rolling results in the decrease of dislocation density from 6.8x1015/m-2 to 3.4x1015/m-2 but both the elastic proportional limit and 0.2% proof stress are markedly increased by contraries. 0.2% proof stress of cold-rolled martensite could be plotted on the extended line of the Bailey-Hirsch equation obtained in cold-rolled iron. It was also confirmed that small amount of cold rolling causes a clear microstructural change from randomly distributed dislocations to cellar tangled dislocations. Martensite contains two types of dislocations; statistically stored dislocation (SS-dislocation) and geometrically necessary dislocation (GN-dislocation). In the early deformation stage, SS-dislocations easily disappear through the dislocation interaction and movement to grain boundaries or surface. This process produces a plastic strain and lowers the elastic proportional limit and 0.2% proof stress in the ultra low carbon martensite.

Cold Deformation Effect on Microstructure and on the Hydrogen Permeability of Low Carbon Al-Killed Steels

2010 ◽  
Vol 659 ◽  
pp. 7-12 ◽  
Author(s):  
Fábián Enikő-Réka
Keyword(s):  
Cold Rolling ◽  
Hydrogen Permeability ◽  
Cold Deformation ◽  
Low Carbon Steel ◽  
Rolling Process ◽  
Low Carbon ◽  
Deformation Degree ◽  
Steel Sheets ◽  
Texture Modification ◽  
Hot Rolled

The cold rolling effect on the hydrogen permeability (TH value) and on the microstructure have been studied on samples prepared from Al-killed low carbon steel sheets after several cold rolling levels. The TH values of the hot rolled strips were very short, but due to the cold rolling increase exponentially. The fragmentation of large cementite phase has a significant influence on the evolution of texture during the cold rolling process. The cold deformation effects on the TH value were studied on four annealed enamelling grade steel sheets also. Depending on the carbides sizes and carbides position in ferrite grains after annealing the TH values increase or decrease after low deformation degrees, due to the steel texture modification and dislocation character. Dislocations act as major tripping site for hydrogen, if deformation degree is higher than 30%.

scholarly journals Potential energy landscape activations governing plastic flows in glass rheology

2019 ◽  
Vol 116 (38) ◽  
pp. 18790-18797 ◽  
Author(s):  
Penghui Cao ◽  
Michael P. Short ◽  
Sidney Yip
Keyword(s):  
Potential Energy ◽  
Strain Rate ◽  
Extreme Values ◽  
Energy Landscape ◽  
Local Strain ◽  
Distance Matrix ◽  
Theoretical Models ◽  
Thermally Activated ◽  
Potential Energy Landscape ◽  
Open Questions

While glasses are ubiquitous in natural and manufactured materials, the atomic-level mechanisms governing their deformation and how these mechanisms relate to rheological behavior are still open questions for fundamental understanding. Using atomistic simulations spanning nearly 10 orders of magnitude in the applied strain rate we probe the atomic rearrangements associated with 3 characteristic regimes of homogeneous and heterogeneous shear flow. In the low and high strain-rate limits, simulation results together with theoretical models reveal distinct scaling behavior in flow stress variation with strain rate, signifying a nonlinear coupling between thermally activated diffusion and stress-driven motion. Moreover, we find the emergence of flow heterogeneity is closely correlated with extreme values of local strain bursts that are not readily accommodated by immediate surroundings, acting as origins of shear localization. The atomistic mechanisms underlying the flow regimes are interpreted by analyzing a distance matrix of nonaffine particle displacements, yielding evidence of various barrier-hopping processes on a fractal potential energy landscape (PEL) in which shear transformations and liquid-like regions are triggered by the interplay of thermal and stress activations.

Texture Evolution during the Cold Rolled Low Carbon Steel Sheet under CSP Technology

2011 ◽  
Vol 121-126 ◽  
pp. 458-462
Author(s):  
Zi Li Jin ◽  
Hui Ping Ren ◽  
Rong Wang
Keyword(s):  
Carbon Steel ◽  
Cold Rolling ◽  
Steel Sheet ◽  
Fibre Orientation ◽  
Texture Evolution ◽  
Low Carbon Steel ◽  
Rolled Steel ◽  
Low Carbon ◽  
Cold Rolled Steel ◽  
Cold Rolled

In this item, the low carbon steel hot sheets by compact strip production (CSP) technology were cold rolled and annealed in laboratory. texture evolution during the production process of CSP-cold rolled strip were investigated by means of the XRD. The results were as follows: After hot deformation of thin slab formed a strong γ- fibre orientation texture, the density of texture increase with the cold rolled reduction increased, especially for the negative texture {100}, in γ-fibre orientation cold rolling texture density has no significant change. Compared to the traditional process, hot rolled steel sheet has higher texture, cold-rolled steel sheet has the same texture, and after-annealing sheet has further higher texture in the CSP-cold rolling process. This study enables better understanding and control on the evolution of textures the cold-rolled steel sheet processed by CSP technique and provides theory support for exploiting the CSP the cold-rolling deep drawing steel sheet

In-Situ TEM Phase Formation in Cold Rolled Aluminum-Nickel Multilayers

1997 ◽  
Vol 481 ◽  
Author(s):  
H. Sieber ◽  
J. H. Perepezko
Keyword(s):  
Cold Rolling ◽  
Phase Formation ◽  
In Situ Tem ◽  
3 Dimensional ◽  
Thermally Activated ◽  
Dsc Measurements ◽  
Sem And Tem ◽  
Rolled Aluminum ◽  
Cold Rolled

ABSTRACTMultilayer samples of Nickel and Aluminum with an overall composition of Al-20Ni were prepared by cold rolling of elemental foils. The sample microstructures and phases were characterized by XRD, SEM and TEM/SAED, and the reactive phase formation was then examined by DSC measurements. XRD, SEM and TEM measurements show that the rolling procedure results in a decrease of the Al and Ni layer thicknesses (down to 100 nm in average) and a decrease of the grain size (down to less than 50 nm). No phase formation is observed during the cold rolling procedure. In isochronal DSC scans of the Al-Ni multilayers, the formation of the Al3Ni phase was found to be a two step reaction process due to 2-dimensional nucleation and lateral growth and a 3-dimensional phase thickening. While XRD measurements showed Al3Ni as the only phase that forms, more detailed TEM investigations of the samples after DSC treatment also showed a small amount of an amorphous Al-Ni phase, formed by a thermally activated solid state amorphization reaction (SSAR). In-situ TEM heating of the amorphous areas under the electron beam in the microscope yielded the crystallization of the amorphous phase to a B2 structure and a growth of the B2 grains up to 100 nm in size.

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