Study on AISI304 sheet metal forming by laser induced thermal stress and its residual stress

A 2.5kW CO2 laser and an X-350A X-ray stress-measuring instrument were adopted in the experiment where stainless steel sheet was studied to evaluate the process parameters of bending with thermal stress induced by laser under the condition of water cooling. Bending angle was measured as the function of processing parameters including power density, laser spot, scan speed, number of passes, and thickness of sheet steel. These processing parameters were arranged according to the theory of orthotropic experiment. The results show that these parameters bring different effects. Number of passes ranks first, followed by energy of laser beam and thickness of sheet metal in terms of their effect on the bending angle, and laser spot, and scan speed are situated in the last two positions for increasing bending angle. Parameters of laser forming also have some influence on the distribution of residual stress on the surface of samples.