Formability of Tailor-Welded Blanks for Steel with Different Thickness and Materials

摘要

With the demands of environmental protection and energy conservation, increasing resources and improving environment, TWB (Tailor Weld Blank) as one of green re-manufacturing technologies will be a guiding orientation in industry. In this study, microstructure of welded joint, tensile test, fracture surface, cupping test of the TWB were carried out. Results show that the microstructure of weld is acicular ferrite and plate pearlite. The microstructure of HAZ beside SAPH440 is pearlite and grain ferrite, and the microstructure of HAZ beside DP600 is numbly pearlite and plate ferrite. The results of tensile test show that the shape of the materials after drawing is not easy to be rebounded, plastic deformation of the blanks is excellent, and the SEM of fracture morphology shows that the fracture is ductile and cleavage when the weld line parallels tensile axis. When the weld perpendicular to tensile axial, the deformation of the TWB is uneven, the plastic deformation is poor and the fracture is typical ductile rupture. The research results of the cupping test suggest that the bulging formability of the TWB is worse than that of base materials, and the bigger proportion of the thin blank in the TWB, the better bulging formability of the TWB.