Title: Preliminary Investigation on SLM of ASTM A131 EH36 High Tensile Strength Steel for Shipbuilding Applications
Abstract:In this preliminary investigation of selective laser melting (SLM) of EH36 high tensile strength steel, a 175 W Yb:YAG laser in continuous wave mode was used to produce EH36 test specimens.The laser b...In this preliminary investigation of selective laser melting (SLM) of EH36 high tensile strength steel, a 175 W Yb:YAG laser in continuous wave mode was used to produce EH36 test specimens.The laser beam profile follows the Gaussian distribution and has a wavelength of 1.064 nm, with a focaldiameter of 81 m.The powder layer thickness was set at 50 m.The stainless steel substrate plate was preheated to 100 °C.The scanning speeds were varied from 260 mm/s to 880 mm/s, and hatch spacing were varied from 0.08 mm to 0.12 mm, to obtain the various energy densities.The highest density value of 7.64 g/cm 3 was obtained at an energy density of 92 J/mm 3 using parameters of 0.12 mm hatch spacing, powder at 175W, 50 m layer thickness and 320 mm/s laser scanning speed.Compared to the relative density of the compacted supplied powder (7.83 g/cm 3 ), the results translated to 97.57% fully dense part.Micrographs were obtained using light optical microscopy, which showedslight porosities in the SLM built part.X-ray diffraction and scanning electron microscropy revealedBCC phases and martensitic microstructure respectively.Read More