Assessment of microstructure of alloy Inconel 686 dissimilar weld claddings

Weld overlay with Ni-based superalloys is an important option for industrial applications. New alloys have been developed to assure desirable characteristics such as corrosion resistance. The Inconel 686 superalloy was developed with a higher Cr and Mo content in order to improve its resistance to corrosion. However, information in the literature about the solidification and weld microstructure of this alloy is very limited. This work, which presents important results concerning the microstructure of the Inconel 686 superalloy, focuses on a detailed analysis of the secondary phases formed during solidification using transmission electron microscopy. The results show that there are several Mo-rich precipitates of the P-phase type in the matrix, and the σ-phase and μ-phase in minor amounts.