Effect of specimen geometry, gage length, and width measurement locations on plastic strain ratio (R-value) in sheet metals

2006 ◽  
Vol 37 (12) ◽  
pp. 3477-3487 ◽  
Author(s):  
A. Chamanfar ◽  
R. Mahmudi
2016 ◽  
Vol 835 ◽  
pp. 203-209 ◽  
Author(s):  
Su Kwon Nam ◽  
In Soo Kim ◽  
Dong Nyung Lee

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.


2007 ◽  
Vol 539-543 ◽  
pp. 3478-3483
Author(s):  
Xiang Zhao ◽  
Chang Shu He ◽  
J. Xu ◽  
Liang Zuo

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.


1992 ◽  
Vol 19 (3) ◽  
pp. 175-188 ◽  
Author(s):  
Dominique Daniel ◽  
J. J. Jonas ◽  
J. Bussière

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.


1985 ◽  
Vol 16 (8) ◽  
pp. 1531-1535 ◽  
Author(s):  
Y. C. Liu ◽  
L. K. Johnson

2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao

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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