Study of weld bead characteristics and optimization during FCAW of AISI 201LN

Abstract

The variant of gas metal arc welding (GMAW) with flux-cored wire is becoming popular in industry and shipyard due to its economy, higher operating current range and better weld quality. Welding of component needs to establish the optimum parameters for obtaining acceptable weld quality with maximizing penetration and minimizing the bead width and reinforcement. In present work, welding investigation is carried out with flux-cored arc welding (FCAW) process on AISI 201LN stainless steel, employing the central composite design (CCD) DoE. The FCAW process uses 100% CO₂ as a shielding gas with flux-cored wire combination which is much economical shielding gas compared to widely used Ar+CO₂ for stainless welding. Wire feed rate (WFR), voltage (V), welding speed (S) and nozzle to work distance (NTD) are considered as weld parameters to investigate the performance of weld bead viz., penetration (P), width (W) reinforcement (R), weld penetration shape factor (WPSF), weld reinforcement form factor (WRFF). The full quadratic models are developed using response surface methodology (RSM) showing good correlations with an average error percentage of 4.41 as minimum for P and maximum as 7.73 for WPSF. WFR, V and NTD are found significant parameters on performance characteristics. The optimization of all responses are performed using desirability analysis and results shows an acceptable composite desirability of 0.6674.