Understanding the humping generation on laser welding process with very thin SS439 films

Rarely research investigates the laser welding process on stainless steel 439 (SS439). Especially the laser welding process with high speed is still a challenging topic for the academic and industrial applications. To address this gap, this study investigated the effect of welding speed from 20m/min to 90m/min. In this research, the appropriate power of welding speed at 20m/min and 40m/min have been verified through Optical microscopy observations and T-Peel test. Furthermore, the study also identified that the humping of SS439 thin sheet is the major defect during the welding process in this research. Last, the dimension measurements of melted region were completed to validate the numerical model with commercial Computational Fluid Dynamics software, and the maximum error rate is 5%.

Advisor: Jingjing Li