Formability of IF- Steel Tailor Welded Blanks (TWBs)

Tailor welded blanks (TWBs) are blanks that including two or more sheet parts varying in materials, coating, thickness, and/or material characteristics that are joined together before forming into the needed piece. Also, interstitial free (IF) steels being free from interstitial atoms do not require over-aging, and it can be manufactured at a rapid heating rate which is significantly employed in the hot galvanizing or continuous annealing furnace. Formability is characterized as a sheet metals capacity to be mechanically formed by plastic deformation without the machining process. To estimate the formability of a metal, patterned sheet forming techniques are employed. The defects have to be estimated distinctly for the primary sheet metal forming systems of deep-drawing and stretching. The discrepancy between these kinds of stamping methods is according to the mechanics of the forming technology. Several technical and numerical models have been improved to determine or analysis the forming limit of sheet metals. Gurson¿Tvergaard¿Needleman (GTN) strategy is one of the well-known microscale models for ductile fracture which is widely applied for various materials and processes.