| Authors |
정재훈(Jae Hoon Chung) ; 김도훈(To Hoon Kim) ; 유병호(Byung Kil Yu) ; 이경돈(Kyoung Don Lee) ; 장낙영(Nag Young Chang) |
| Abstract |
This work is the basic research on the tailored blank laser welding between different thickness automobile low carbon steel sheets. The materials used were low carbon steel sheets for automotive bodies, which were welded together in different thickness(0.9㎜/2.0㎜). In order to make a practical application of the tailored blank laser welding method in automobile industry, optimum conditions for laser welding should be obtained. Experiments were carried out and analysed by applying the Taguchi method. Optical microscopy, SEM, TEM and XRD analysis were performed to observe the microstructures in the fusion zone. In 0.9/2.0 welding, the proportion of lower transformation temperature phases has found to be increased in comparision to the 0.9/0.9 welding. Since an important property of tailored blank laser welding method is formability, the formability of the base metal and welded specimens were examined through tensile test, dome height test, microhardness test. The elongation and LDH of welded specimens were more than 70% of the base metal in the case of 0.9/2.0 welding. |