Investigation of the effect of tube bending parameters on the mechanical properties of E235 steel used in precision tubes in the automotive industry

Steel materials are among the most widely used building materials in engineering applications due to their superior mechanical properties such as high strength, good ductility, weldability and ease of forming. These materials are preferred in the production of critical components in many industrial areas such as automotive, construction, energy, defense and machine manufacturing. Especially E235 steel, which is in the low carbon steel class and produced in accordance with the EN 10305-3 standard, is widely used in many different areas such as the automotive industry, energy transmission systems, heating-cooling lines and precision mechanical parts in pipe form. In these applications, changes in the mechanical and geometric properties of the material during pipe forming processes can directly affect both the performance and service life of the product. Therefore, a detailed understanding of the material behavior after forming is of great importance. In this study, the mechanical and structural changes that E235 steel is exposed to during the rotary draw bending process were systematically investigated. Within the scope of experimental studies, different bending parameters, especially bending radius and bending angle, were changed and the effects of these variables on the deformation behavior of the material were evaluated. With the tensile tests performed, the yield strength, maximum tensile strength, elongation at break and elastic-plastic transition zones of the samples before and after bending were comparatively examined. At the same time, the effects on geometric precision were analyzed by measuring the springback amounts formed after bending. In addition to the experimental studies, numerical modeling was performed with the finite element method in order to examine parameters such as stress distributions, thickness changes and section deformations on the pipes in more detail. The simulation data were compared with the experimental findings and verified, and the obtained results were explanatory in terms of the bending behavior of the material. This study not only reveals the forming performance of E235 steel, but also provides engineering data that can directly contribute to process design, quality control, cost optimization and product development processes for manufacturers working with similar steel materials. Especially in sectors such as the automotive industry where precision pipe components are produced, such data is important in reducing production errors and achieving more stable product designs.