2023 Volume 64 Issue 755 Pages 225-230
The application of high-strength steel sheets to automobile parts is expanding year by year. As a method of processing high-strength steel sheets, cold stamping is superior in cost and productivity, but it also presents many problems. One of the major problems of cold stamping is the low dimensional accuracy of components caused by springback. Springback is an elastic recovery phenomenon at the time of tool release after press forming, and there are various deformation forms depending on the shape of the part. Although measures against each form of springback have been examined and practical applications are advancing, there are many cases in which multiple forms of springback occur in actual automobile parts but there are only a few cases in which the mutual effects of these forms and combinations of countermeasure technologies have been discussed. In this study, we evaluated the mutual effects of each shape change on parts where opening and twisting springback occur simultaneously and discussed the mechanism of these shape changes. We also describe countermeasure technologies for each springback type and give examples of how combining such technologies can effectively reduce both types of springback. In this study, both open and twist composite springback could be reduced by more than 70%.
