Determination of Mechanical Properties and Fracture Behavior of Hot-Rolled Inconel 617/Ni Bimetal Composite Plate

Molten salt reactors (MSRs), which represent a widely implemented reactor type, are subject to severe conditions, which significantly impact structural materials. Hence, in this study, the bimetal composite plate (Inconel 617/Ni-201) was developed by hot rolling to meet the demands of alloy structural materials employed in future high-temperature MSRs. The results of the bending test indicate that the interface of the two metals was well bonded. The tensile properties and microstructure, especially at the bimetallic interface of the composite plate, were tested and characterized using tensile testing machine, transmission electron microscopy (TEM), and scanning electron microscopy. TEM analysis of the bimetal interface confirmed that the two materials were in a metallurgical bonding state. Moreover, the tensile properties of the bimetal composite plate were mainly determined by the Inconel 617. In addition to the elongation at room temperature, the tensile properties of the composite plate were superior to those of Hastelloy N alloy, which is a well-known and potential structural material for use in MSRs. In this study, the tensile properties of the composite plate after long-term high-temperature aging were also tested to determine its applicability to future high-temperature MSRs.