A combined experimental-numerical approach has been developed to quantify the strain rate variation of the workpiece in the roll bite region. In this approach, cold rolling experiments at a production mill were conducted first. Then, tensile and microhardness tests were performed on workpieces before and after cold rolling to establish the relationship between the microhardness and plastic strain of the material. Microhardness measurements were also conducted in the roll bite region on a partially cold rolled workpiece. A finite element rolling simulation was performed to predict the spatial variations of the strain and strain rate. Through microhardness matching, it was found that the finite-element predicted strains agree very well with those actually existing in the rolled workpiece. Consequently, the finite-element predicted strain rates, whose time-accumulation directly gave strains which matched the actual strains, were verified. Finally, a finite-element simulation of both cold and hot rolling was conducted to assess the effect of several major rolling parameters on the strain rate variation in the bite region. Results show that the spatial variations of strain rate in the roll bite region are extremely nonunifonn for both cold and hot rolling.
[1]
Hugh W. Coleman,et al.
Experimentation and Uncertainty Analysis for Engineers
,
1989
.
[2]
Ampere A. Tseng,et al.
Mechanical and bending characteristics of invar sheets
,
1996
.
[3]
A. Laasraoui,et al.
Recrystallization of austenite after deformation at high temperatures and strain rates—Analysis and modeling
,
1991
.
[4]
Shiro Kobayashi,et al.
Metal forming and the finite-element method
,
1989
.
[5]
Ampere A. Tseng,et al.
Roll cooling and its relationship to roll life
,
1989
.
[6]
M. Zehetbauer,et al.
Microhardness and yield stress of cold rolled pure aluminum up to very high deformation
,
1983
.
[7]
Ampere A. Tseng,et al.
Macro- and micro-modelling of hot rolling of steel coupled by a micro-constitutive relationship
,
1995
.
[8]
A. A. Tseng.
Material characterization and finite element simulation for forming miniature metal parts
,
1990
.