PROCESS PARAMETER OPTIMIZATION FOR ADDITIVELY MANUFACTURED STAINLESS STEEL 316L PARTS BY SELECTIVE ELECTRON BEAM MELTING

An experimental study of process parameter optimization for stainless steel 316L (SS316L) parts additively manufactured by selective electron beam melting (SEBM) was carried out. The process parameters for different stages, particularly in the in-fill hatch melting stage, were optimized in this study. Near-fully dense (>99%) SS316L parts have been successfully fabricated with well-melted surfaces. Microstructural characterization was performed on the as-SEBM-built SS316L parts with the optimal process parameters. It revealed that near-equiaxed grains were formed, which is distinctive from the counterparts additively manufactured by other SEBM processes. The mechanism for the formation of near-equiaxed grains was discussed in detail. This paper provides an insight into fabricating SS316L parts with high density and desirable microstructure via SEBM process.