Optimization of flux metal arc welding parameters for productivity and quality in dissimilar metal welding

The shielded metal arc welding (SMAW) process is a widely used process. A common problem with the process is the loss of material in terms of stub loss, and frequently changing electrodes that consume much time, interrupting the process's continuity. To overcome this issue, an auxiliary flux feeding method- flux metal arc welding (FMAW)- is proposed for surfacing, joining and hard-facing applications enabling continuous welding without interruption and material loss and achieving a higher deposition rate at a lower deposition current. The current work uses FMAW process for cladding operation i.e. a dissimilar welding of stainless steel layer over carbon steel. This paper investigates the effects of proposed FMAW process parameters on metal deposition rate and percentage dilution for dissimilar metal welding. Weld beads have been laid down on a mild steel plate by adjusting process parameters, such as open-circuit voltage, current, welding speed, nozzle-to-plate distance, and flux flow rate, as per the central composite design. The responses have been compared with the established conventional gas metal arc-based additive manufacturing, also called wire additive manufacturing (WAAM). The interrelations between process parameters and responses have been established using multiple linear regression. The effects of individual parameters and their interactions on responses have been studied in the proposed process. Finally, single and multi-objective optimization was performed using the grey wolf optimization (GWO). The results reveal that a modified process can achieve a higher metal deposition rate with lower dilution. The FMAW process provides 47.47 % more metal deposition rate and 35.63 % lower dilution than the GMAW process.