Abstract
In the automotive industry, it is required to reduce weight of the car and improve fuel efficiency. Competitive pricing is also a very important issue. That's why application of welded steel tube is increasing in order to produce a vehicle with a competitive price. Also, hydroforming technology is asking more and more for thinner tubing to realize to a lighter vehicle design. Steel tube is produced through a multi-stage process called roll forming. In that case, bucking and work hardening should be considered key forming technology is to prevent buckling and minimize work hardening during steel tubing for hydroforming To prevent buckling, it is required to optimize forming process in order to minimize stretching in edge sections and hold tightly cross-section during welding. And to minimize work hardening, it is needed to know the proper process to avoid reforming.
