Forming technique for cold rolled steel produced by PT Krakatau Steel for national electric vehicle body materials

摘要

Demand for automobile in Indonesia increases significantly in the latest decade. Therefore, competitiveness for each automobile manufacturer is tight. One of options to improve competitiveness, manufacturer has to use local material. As the result, manufacturing cost and car unit cost also decreases. This condition not only happened in internal combustion engine vehicle but also for electric vehicle. Therefore the challenge is facing when using local steel sheet material for auto body panel and structure. One of the main focuses in the ability to produce complex shape without visual defect and failure named as forming ability. In this paper we propose new forming technique to improve forming ability for the local steel sheet produce by PT Krakatau Steel. Even though conventional stroke is able to produce cup without crack, but winkle is still exist that produce visual defect. The new approaches are applying step motion of the punch stroke. By applying step motion materials has enough for relaxation before further deformation. As the result deep drawing process that implement step motion exhibit free from wrinkle and uniform thickness.