Structure, chemical composition and mechanical properties of MIG-CMT-Cladded Inconel 625/16Mo3 bimetallic layers

Abstract The demand for materials capable of reliable service at elevated temperatures is steadily increasing. Therefore, this research presents the manufacturing process of MIG-CMT linear Inconel 625 cladding onto the 16Mo3 base material to create high efficiency and corrosion resistant bimetallic material. Microstructure of the bimetallic material was examined by SEM, which revealed NbC, TiC, and MoC carbides within the structure and dendrites that were directionally solidified and aligned parallel to the thermal gradient. Dislocation in microstructure was examined by TEM analysis. The grain size and orientation were examined by EBSD analysis, which found that the grain size in heat affected zone was on average about 10 µm. Furthermore, the chemical analysis unveiled that the chemical composition of Fe decreased from the average value of 3.5–1.2% after overlapping with the second Inconel 625 layer. Micro-CT analysis showed that the bimetallic material exhibited minimum internal defects due to the appropriate welding parameters. Microhardness testing revealed that the highest value of hardness was measured between welded layers 398 HV0.1. The base 16Mo3 material exhibited a average hardness of 210 HV0.1. It was concluded that bimetallic material consisted of Inconel 625 and 16Mo3 steel offers a robust solution for industrial environments requiring high strength, corrosion resistance, and thermal stability such as the incinerating kettle.