Evaluation of Formability and Mechanical Behavior of Laser-Welded Tailored Blanks Made of Interstitial-Free and Dual-Phase Steels

摘要

An attempt has been made to produce laboratory scale laser-welded tailored blanks (LWTBs) with interstitial-free (IF, 300 MPa) and dual-phase (DP, 590 MPa) steel sheets with a thickness ratio of 2. Microstructures and textures of the base, weld, and heat-affected zones (HAZs) were examined using the scanning electron microscope and electron backscattered diffraction technique. The blanks were deformed using the standard limiting dome height (LDH) test setup, and the forming limit diagrams (FLDs) for base IF, DP, and welded blanks with two different weld orientations were constructed. The findings suggest that the FLD_o of the welded blank lies in between that of parent IF and DP steel sheets. The formability of the welded blank is highly influenced by the weld orientation. The location of crack formation in the blanks changed with changing the weld orientation in the blanks. The formation of crack on different locations of the blank has been correlated with the local textural differences.