Development of optimal deposition strategies for cladding of Inconel 625 on carbon steel using wire arc additive manufacturing

The use of nickel alloys for cladding and repair has a high scientific and industrial interest in surface engineering. The use of smart processes for surface modification, such as additive manufacturing, particularly wire arc ad-ditive manufacturing (WAAM), is relevant due to its high deposition rate and capacity for customisation and deposition over complex geometries and paths. The present research is focused on strategies for cladding Inconel 625 on low-carbon steel using WAAM, investigating the effect of different welding parameters to control and optimize the penetration, geometry, dilution, and overall quality. Parameters such as the torch/table travel angle, welding technique, contact-tip-to-work distance, current/wire feed speed (WFS), welding travel speed and heat input were analysed. Three deposition strategies were developed: the deposition with a shorter contact-tip to-work distance to increase penetration resulting in the least iron-containing clad; the welding with a higher WFS but with a proportional increase in the travel speed to maintain the heat input allowing faster welding and adequate iron content; and the welding with higher WFS and lower travel speed resulting in a thicker clad and the second least iron-containing deposition. It was found that the arc power showed a more direct relationship with the penetration and dilution in the clad than the heat input. The results suggest that for cladding evaluation, it is important to analyse the heat input together with the arc power and travel speed.