Springback of High-Strength Steel after Hot and Warm Sheet Formings

The springback of high-strength steel after hot and warm sheet formings is investigated. Environmentally friendly vehicles will promote the increasing usage of high-strength steel sheets, however, a large amount of springback after sheet forming is one of the major drawbacks. A series of hot and warm sheet forming experiments on high-strength steel sheets are conducted using a hot compression testing machine, and the effect of forming temperature on the amount of springback is evaluated. The springback is markedly reduced when the forming temperature is higher than 750K, which is approximately the critical temperature for the recrystallization of ferrite grains.