The automotive industry is exhibiting the trend of positively adopting stainless steel pipe as one of the means for improving weight reduction and rust resistance. In particular, austenite stainless steel pipe (hereafter referred to as “SUS pipe”) is widely used in automotive parts due to its excellent rust resistance, heat resistance, and magnetic properties. Nevertheless, reports regarding the forming technology of SUS pipe are rare. In particular, reports on the thin-sheet SUS pipe, which this paper discusses, are extremely rare.
Up until now, the application of SUS pipe for various parts consisted primarily of 1.0mm-thick materials. The thin-sheet SUS pipe material is known to be difficult to shape because of its low sheet rigidity relative to the forming force, resulting in wrinkles and buckling. Moreover, it is susceptible to galling in the die due to the hardness of the material, making it also difficult to shape.
In this study, for the purpose of bending and expanding the thin-sheet SUS pipe material (with a maximum thickness of 0.5mm), we adopted the forming conditions in which the material characteristics of SUS pipe are taken into consideration. As a result, we were able to adopt an ultra-thin sheet SUS pipe material with a thickness of 0.5mm to automobile fuel filler pipe application.