The effects of material thickness and deformation speed on springback behavior of DP600 steel

There is an increase trend in the use of advanced high strength steels in automotive industry due to a combination of high strength and good formability in order to achieve substantial weight reduction. Lightening by using thinner advanced high strength steel sheets is effective to provide better performance than current structures. In recent years, the usage of DP600 steel in automotive industry has been increased remarkably. However, high strength usually increases the springback behavior which creates serious problem in the assembly line. Springback is a very complex behavior and not easy to be eliminated. This problem limits the usage of these types of steels, increases part cost and reduces part quality. Springback free or minimum springback observed parts are one of the important goals of automotive industry in terms of cost and quality. In this study, the effects of deformation speeds, sheet thickness, and widths on the springback were investigated experimentally and numerically using a 60o V-shaped bending for DP600 steel. Results reveal that the springback was significantly decreased with increasing thicknesses and deformation speed except for 500mm/min deformation speed. The effects of widths on springback were found to be inconsiderable.