Finite element analysis of the formability of an austenitic stainless steel sheet in warm deep drawing

The forming limit in warm deep drawing of a type 304 stainless steel sheet is experimentally examined and the deformation behaviour and the temperature change in the sheet are simulated by the combination of the rigid-plastic and the heat conduction finite element methods. In the simulation the deformation-induced martensitic transformation is taken into consideration. The experimental and the numerical results show the positive effect of the heating on the drawability. The limiting drawing ratio becomes higher to 2.7 in the warm deep drawing, while the ratio is 2.0 at room temperature. The improvement in the drawability is attained by the comparatively low heating temperature under 150 degreesC and by the cooling of the punch. The forming limit and the necking site are successfully predicted by the simulation. (C) 2003 Elsevier Science B.V. All rights reserved.