Laser welding of advanced high strength steels

Více o knize

This research focuses on the characterization of CO2 laser beam welding (LBW) of dual phase (DP) and transformation induced plasticity (TRIP) steel sheets through experimental, numerical simulation, and statistical modeling approaches. The experimental work investigated the welding-induced microstructures, hardness, tensile properties, and formability limits of laser-welded butt joints of DP/DP, TRIP/TRIP, and DP/TRIP steel sheets at varying welding speeds. Additionally, the effects of different shielding gas types and flow rates on the weldability of DP/TRIP steel sheets were examined. The second goal involved simulating the laser welding process for DP/TRIP steel sheets, focusing on the welding-induced temperature field, thermal cycles, residual stresses, and distortions using Sysweld 2010 software. Stretch formability was also simulated using Abaqus/CAE software. Statistical modeling aimed to predict and optimize the laser welding process in industry by applying a three-factor-three-level Box-Behnken design of experiments (DoE) approach, controlling parameters such as laser power, welding speed, and focus position. The results demonstrated that CO2 LBW effectively joins DP and TRIP steel sheets. Numerical simulations using a 3D Gaussian heat source model showed good agreement with experimental results, particularly in predicting stretch formability using the von Mises yielding model. Mathematical models were developed t