Microstructural banding of directed energy deposition-additively manufactured 316L stainless steel

摘要

The microstructures of 316L stainless steel created by rapid solidification are investigated by comparing the similar microstructures of individual hatches of directed energy deposition additive manufacturing(DED-AM)and those of single,laser surface-melted tracks formed on a solid plate.High recoil pressure,which is exponentially dependent on the laser beam power density,induces convection of the melt pool,which causes formation of microstructural bands in the as-solidified microstructure.The microstructural bands are associated with changes in the chromium concentration and are a significant component of the inhomogeneous microstructure of DED-AM.