Stainless steel sheets are increasingly used for making different parts because of
their high corrosion-resistivity and good appearance. Nevertheless, under cold forming
conditions the high content of martensite in such material due to the accumulated
strain in forming process brings the rise in working force, the decrease in corrosionresistivity,
the magnetization and the delayed cracking. To avoid the martensitic transformations
and omit the annealing process, warm forming is useful, since the martensitic
transformation decreases with increasing temperature. This needs make sheet metal
forming operations of stainless steel more complex than those performed on other
materials because of the increase in number of process parameters affecting the deformation
mechanisms at high temperatures. As a matter of fact, the occurrence of
microstructural phenomena: grain growth, surface oxidation, friction condition, etc.,
can make the material sensitive to strain rate and temperature. As a consequence, the
prediction of phenomena affecting the accuracy of the final product, such as the
springback, that is the partial return of the sheet to its initial shape when forming load
is removing, can be very difficult and more complex than the one in cold forming
conditions
conditions) on springback quantity was performed in air bending test. The MSC Marc Mentat commercial
computer code was used for numerical simulation of analyzed forming processes.