マルエージング鋼積層造形体の機械的特性に対する粉末酸素濃度の影響

抄録

L-PBF (Laser-Powder Bed Fusion) is a kind of AM (Additive Manufacturing) process in which a part is bult in a layer-on-layer manner. In this study, the mechanical properties of maraging steel (Fe-18Ni-9Co-4.8Mo-Ti-Al) manufactured by L-PBF (Laser-Powder Bed Fusion) using powders with different oxygen content were investigated. As a result, nitrogen content of specimen manufactured remained unchanged compared with that of powder, while oxygen content of specimen increased compared with that of powder. In the tensile test and Charpy impact test,ultimate tensile strength and 0.2% proof stress of specimens were equivalent with regardless different oxygen content . However, the ductility and impact toughness of the specimen were significantly decreased with increasing oxygen content. In addition, fractured surface of caused by oxide inclusion was sometimes confirmed in specimen with high oxygen content. Thus, it is suggested that ductility and impact toughness of the specimen manufactured depend strongly on the increase oxygen content.