The formability and springback characterization of laser-welded DP–HSLA sheets

Abstract

This study experimentally investigated the formability and springback behavior of dualphase (DP600) and high-strength low-alloy (HSLA) sheets bonded with a laser beam welding. In the initial stage of the study, DP600 and HSLA sheets were bent in V-bending dies and their springback behavior was investigated. In the later stage of the study, DP600–HSLA sheets bonded with a laser of three different power levels (1400 W, 1500 W, 1600 W) were bent in V-bending dies to investigate their springback behavior. In addition, changes in the metallurgical structure were investigated at the points where the pieces were welded together and the effect on springback characteristics was evaluated. As the power of laser increased from 1400 to 1500 W, the springback angle increased by 12.1% on average, whereas when the power was increased from 1500 to 1600 W, the springback angle decreases by 17.6%. An increase of 15° in the die angle increases the springback angle by 10.4% on average up to 45°; whereas beyond 45°, it decreases the springback angle by an average of 73.6%. For a 10-s increase in holding time, it was determined that springback angle decreased by 21.2% on average.