Wrinkling behaviour of interstitial free steel sheets when drawn through tapered dies

Wrinkling is a mode of failure commonly observed in the forming of sheet metals during deep draw operation. An experimental study on wrinkling behaviour of interstitial free (IF) steels through conical and tractrix dies is discussed in this paper. Mechanical properties and drawability parameters of these IF steels were determined and they were correlated with the wrinkling behaviour. The limiting draw ratio (LDR) of these steel sheets were related to the sheet thickness, the ratio of punch diameter to sheet thickness, the normal anisotropy and the non-dimensional parameter (which involves punch diameter, sheet thickness, normal anisotropy and strain hardening exponent). The above study of wrinkling behaviour was carried out under two different conditions namely lubricated and non-lubricated and they were compared. From the study, it is clear that the LDR could be related to the above-mentioned parameters.