scholarly journals The Elastic Strain Ratio, the Lüders Strain Ratio and the Evolution of r-Value During Tensile Deformation

1992 ◽  
Vol 19 (3) ◽  
pp. 175-188 ◽  
Author(s):  
Dominique Daniel ◽  
J. J. Jonas ◽  
J. Bussière
Keyword(s):  
Quantitative Analysis ◽  
Plastic Strain ◽  
Deep Drawing ◽  
Elastic Strain ◽  
Tensile Deformation ◽  
Empirical Relationship ◽  
Strain Ratio ◽  
Plastic Strain Ratio ◽  
R Value ◽  
Lüders Bands

The elastic counterpart of the plastic strain ratio is derived from ultrasonic data measured on twenty commercial deep drawing steels. It is shown that the observed variations in plastic r are related to the evolution of texture, and are not affected either by the elastic range of deformation or by the propagation of Lüders bands. Further quantitative analysis suggests that the elastic strain ratio, determined non-destructively, can be used to predict plastic r-values by means of an empirical relationship.

Improvement in Plastic Strain Ratio of AA1050 Al Alloy Sheet by Enhancing the <111>//ND Texture Component

2016 ◽  
Vol 835 ◽  
pp. 203-209 ◽  
Author(s):  
Su Kwon Nam ◽  
In Soo Kim ◽  
Dong Nyung Lee
Keyword(s):  
Plastic Strain ◽  
Anisotropy Parameter ◽  
Strain Ratio ◽  
Alloy Sheet ◽  
Subsequent Annealing ◽  
Al Alloy ◽  
Asymmetric Rolling ◽  
Plastic Strain Ratio ◽  
R Value ◽  
Average Plastic Strain Ratio

The average plastic strain ratio (the R-value) and the anisotropy parameter |ΔR| calculated from the measured texture of AA1050 Al alloy sheet treated by the heavy asymmetric rolling by 84% reduction in thickness and subsequent annealing for 1 h at 500 °C, followed by light rolling by 10% or 20% reduction in thickness and the subsequent annealing for 1 h at 500 °C increased by 1.52 times that of the non-processed specimen and reduced to 1/12 times that of the non-processed specimen, respectively.

scholarly journals Physical Modelling and Numerical Simulation of the Deep Drawing Process of a Box-Shaped Product Focused on Material Limits Determination

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1058 ◽  
Author(s):  
Miroslav Tomáš ◽  
Emil Evin ◽  
Ján Kepič ◽  
Juraj Hudák
Keyword(s):  
Plastic Strain ◽  
Deep Drawing ◽  
Scaling Laws ◽  
Strain Ratio ◽  
Physical Models ◽  
Scale Model ◽  
Drawing Process ◽  
Plastic Strain Ratio ◽  
Thickness Change ◽  
Deep Drawing Process

Similitude theory helps engineers and scientists to accurately predict the behaviors of real systems through the application of scaling laws to the experimental results of a scale model related to the real system by similarity conditions. The theory was applied when studying the deep drawing process of a bathtub made from cold rolled low carbon aluminum-killed steel from the point of view of material limits. The bathtub model was created on the basis of geometric, physical, and mechanical similarity on a scale of 1:5. Thus, simulations and physical models were created. The simulation model was used to verify the combination yield locus/hardening law on the basis of comparing the thickness change. As a result, Hill 48/Krupkowski showed the minimal deviation by comparing data evaluated from numerical simulations and that measured on the physical model. Additionally, material anisotropy was modelled when virtual materials were defined from experimentally measured values of the plastic strain ratio. As an outcome, extra deep drawing quality steel with an average plastic strain ratio of rm ≥ 1.47 and an average strain hardening exponent of nm ≥ 0.23 must be used for the deep drawing of the bathtub.

Effects of Electric Field Annealing on Recrystallization Texture and Plastic Strain Ratio (r-Value) of IF Steel Sheet

2007 ◽  
Vol 539-543 ◽  
pp. 3478-3483
Author(s):  
Xiang Zhao ◽  
Chang Shu He ◽  
J. Xu ◽  
Liang Zuo
Keyword(s):  
Plastic Strain ◽  
Electric Field ◽  
Steel Sheet ◽  
Strain Ratio ◽  
Fiber Texture ◽  
If Steel ◽  
Plastic Strain Ratio ◽  
Field Annealing ◽  
R Value ◽  
If Steel Sheet

Effects of electric field annealing on recrystallization texture and average plastic strain ratio (r value) of IF steel sheet were studied by mean of X ray diffraction ODF analysis and the tensile test. Specimens of 75% cold-rolled IF steel sheet were annealed at 850flC for 25min,with and without electric field annealing respectively. Results show that the electric field annealing does not change the type of recrystallization texture and its formation mechanism in IF deep-drawing steel sheet, but improves the formation and development of recrystallization i-fiber texture, enhances the intensity of i-fiber texture, and retards the formation and development of c-fiber texture. Comparing with the conventional annealing, electric field annealing improves the average plastic strain ratio (r value). Possible reasons for the intensification of recrystallization i-fiber texture with the electric field applied may attribute to the reduction of stored energy, thus hindering the formation of other orientated nuclei and enhancing the nucleating ratio of i-oriented nuclei. And the intensification of recrystallization i-fiber texture was considered as the main reason for the enhancement of the plastic strain ratio (r value) in IF steel sheet.

Calculation of Plastic Strain Ratio of Deep-Drawing Steel Sheets from Texture

2002 ◽  
Vol 408-412 ◽  
pp. 1103-1108
Author(s):  
Q.W. Jiang ◽  
Yu Dong Zhang ◽  
X. Zhao ◽  
Z.D. Liang ◽  
Fu Hui Wang ◽  
...  
Keyword(s):  
Plastic Strain ◽  
Deep Drawing ◽  
Strain Ratio ◽  
Plastic Strain Ratio ◽  
Steel Sheets

scholarly journals Evolution of r-Value During the Tensile Deformation of Aluminium

1995 ◽  
Vol 23 (3) ◽  
pp. 149-171 ◽  
Author(s):  
J. Savoie ◽  
J. J. Jonas ◽  
S. R. Macewen ◽  
R. Perrin
Keyword(s):  
Plastic Strain ◽  
Single Crystal ◽  
Elastic Constants ◽  
Crystal Plasticity ◽  
Elastic Strain ◽  
Tensile Deformation ◽  
Pure Aluminum ◽  
Strain Dependence ◽  
R Value ◽  
Lüders Band

The elastic strain ratios associated with specific ideal orientations as well as with particular experimental textures were derived from the second order Hill approximation. The single crystal elastic constants for pure aluminum and copper were used. Plastic strain ratios were then calculated for the experimental textures using the FC (full constraint), RC (relaxed constraint) and LW (least work) crystal plasticity codes. Tests were also carried out to determine the r-values along various directions in the sheet during Lüders band propagation, as well as the dependence on strain of the plastic r-value. It is shown that the observed strain dependence of the r-value is related to Lüders band propagation and to the evolution of the texture and not to the elastic-plastic transition.

Determination of Optimal Coiling Temperature and Cold Reduction Ratio of 260MPa Grade High Strength Nb-IF Steel

2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
N Value ◽  
R Value

Hot rolled 260MPa grade high strength Nb-IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization has finished. Under 650°Ccoiling temperature and 75% cold reduction ratio, and under 600°C or 700°C coiling temperature and 65% cold reduction ratio, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, and respectively, the r value was approximate 1.8, the n value was approximate 0.26. That obtains optimally match of high strength and punching property.

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