Investigation on Three-Dimensional Laser Bending of Steel Sheets

Despite its advantages over traditional approaches, 3D bending by laser forming process causes significant microstructural changes because of its thermal nature. The 3D laser bending strategy which contains the overlapped passes is of interest from microstructuralpoint of view. Present study focuses on microstructural characterization of AISI 316 stainless steel sheets which were bent by 3D laser bending via raster scanning approach. The results showed that by applying a very small pass spacing of 0.5mm with small beam diameter of 0.5mm, the material is affected by melting and subsequent formation of martensite. But relatively high amount of deformation is achieved due to subsequent scanning. Using short pass spacing, it is also possible to improve ductility by gaining a homogenizedmicrostructure. The application of high laser energy input during the overlap ratios of 0.5 and 0.62 results ina fine microstructure composed of ferrite grains. The increase in size of the heat affected zones in the sample with overlap ratio of 0.62 introduced the gradient in microstructure.

Keywords:

3D laser bending , scanning strategy , AISI 316 stainless steel