The influence of hatch spacing on the metallurgical characteristics of 17–4 PH stainless steel processed by DED

Abstract

The quality and performance of additively manufactured part is linked to the process parameters such as laser power, scanning speed, powder feed rate, and layer thickness. However, hatch spacing is one of the process parameters that affect the quality and performance of the part, but its effect has not been fully investigated. Therefore, this study seeks to investigate the effect of hatch spacing on the metallurgical characteristics, including microstructural evolution, microhardness, and corrosion behavior of 17–4 PH stainless produced through direct energy deposition. A LENS system was used to manufacture 17–4 PH SS cubes and the hatch overlap was varied from 20 to 80%. Subsequently, the printed cubes were subjected to heat treatment (H900) followed by material characterization which includes microstructural analysis, microhardness, and corrosion behavior. This study deduced that varying the percent overlap had an impact on the proportion of delta ferrite and the grain size. Furthermore, increasing the percent overlap from 20 to 80% was found to cause a reduction in hardness (340–331 HV). Meanwhile, it was found that traditionally manufactured 17–4 PH SS is more susceptible to corrosion than additively manufactured 17–4 PH SS.