Recently, there are many opportunities to see the term of MPHL in papers on cold sheet rolling. The MPHL model has been used in order to explain the phenomenon that the coefficient of friction decreases with increasing cumulated reduction in cold sheet rolling. However, the behavior of MPHL in cold sheet rolling is not known in detail. Therefore, it is necessary to investigate the occurrence condition of MPHL in cold sheet rolling, and the effects of tribological factors on MPHL. In this paper, first an experimental method using a laboratory rolling mill was proposed to confirm the MPHL behavior in cold sheet rolling. Second, rolling experiments were conducted using the developed experimental method to confirm the MPHL behavior and moreover a numerical modeling was developed in order to quantitatively understand the MPHL behavior. Third, the effects of tribological factors on MPHL were investigated by the experimental method and numerical modeling.
Azushima et al. (Fri,) studied this question.