Determination of Warm Deep Drawing Behavior of DP590 Steel Using Numerical Modeling and Experimental Process Window

The present work focuses upon the determination of deep drawing behavior of DP590 steel under different lubricating and warm forming conditions. The limiting drawing ratio (LDR) was observed to be 1.933 under 673K_Lubricated condition which is 3.53% more than other processing conditions. The modified Johnson–Cook (m-JC) and Johnson–Cook and Zerilli–Armstrong (JC–ZA) constitutive models have been used among which the JC–ZA model along with Hill'48 r-based displayed the best prediction ability of flow stress and yield locus, respectively. The stretch forming process has been performed to find the safe forming limits of the material and an effective improvement of 24% has been observed as the temperature increased from 300 to 673 K. Further, the adequate lubrication helped in increasing the strain ratio, thus, helped in increasing the range of limiting strains. The strain-based FLD has been converted into stress based and triaxiality and equivalent plastic strain FLD in order to remove excessive dependency over limiting strains. The deep drawing deformation path has been found to be lying in the uniaxial stress region of FLD. The best numerically predicted results of thickness distribution and drawn height have been obtained using the combination of Hiil'48 r-based yielding function and JC–ZA constitutive model. The coupled effect of high temperature and lubricating condition helped in increasing the LDR and the uniformity in thickness distribution along the walls of the deep drawn cup and further helped in reducing the maximum load needed for forming the cup.