Influence of torch oscillation on the microstructure of Colmonoy 6 overlay deposition on SS304 substrate with PTA welding process

Abstract

Colmonoy 6 alloy has been regarded as an efficient overlay material for various grades of substrate materials. The PTAW process has been emerged as a very useful process to deposit such materials effectively. Torch oscillation may become an efficient PTAW parameter to achieve a desired microstructure due to its significant advantage over liner torch movement due to a faster cooling of the weld pool. Proposed work aims to analyse the influence of torch oscillation on the microstructure of Colmonoy 6 overlay surface on SS304 substrate. The structure of the surface deposited with PTAW torch oscillation shows increase in the Cr concentration in δ-Cr7C3, θ-(Cr, Fe)7C3 and μ-Cr23C7 phases upon characterization by SEM with EDS and XRD. This decreases the solidification temperature of Ni-based soft matrix which provides a higher hardness of the coating. These outcomes can also come handy for other grades of materials to control their metallurgical characteristics effectively.