Development of 316L-0.3Y2O3 ODS steels by selective laser melting

Oxide-Dispersion-Strengthened (ODS) steel has developed into one of the most promising structural materials for advanced nuclear reactors. However, the traditional preparation method of ODS steel, powder metallurgy (PM), has many problems and defects in the manufacturing process. As such, we attempt to use an additive manufacturing technology, selective laser melting (SLM), to print out the desired ODS steel. This dissertation investigated the feasibility of SLM for the preparation of ODS steel. Y2O3 powder (mass fraction: 0.3%) was mixed with 316L stainless steel powder by low-energy ball milling method, and then the mixed metal powder was printed using SLM technology. Besides, the microstructure and mechanical properties of the 316L-0.3Y2O3 ODS steel were investigated in comparison with 316L stainless steel. The obtained show that the printing effect on 316L-0.3 Y2O3 ODS steel is quite good by using SLM technology. In addition, the hardness of ODS steel has also been improved. However, it was also observed that there are more pores in the 316L-0.3 Y2O3 ODS steel as compared with 316L steel, and Y2O3 agglomeration was observed on the top surface. Master of Science (Mechanical Engineering