Parametric optimization and performance prediction of stainless-steel ER308L cladding on mild steel via gas metal arc welding using RSM

The study is centered around the optimization of parameters and performance prediction for ER308L stainless steel welding on mild steel substrates using the Gas Metal Arc Welding (GMAW) process. The systematic alterations of the process variables (welding current, arc voltage, and travel speed) accompanied by Response Surface Methodology (RSM) grounded on Central Composite Design (CCD) aim at enhancing not only the surface characteristics but also the strength of the bond. The effect of factors on the critical reactions was determined by clad hardness, tensile strength, and dilution using statistical modeling and analysis of variance (ANOVA). The experimental validation confirmed that the regression models in question were extremely precise, as indicated by the correlation coefficients (R² > 0.97) between predicted and experimental values. The response surface and desirability plots revealed that an ideal heat input condition (moderate current and voltage with controlled travel speed) has led to an enhancement in clad properties—maximum hardness of approximately 360 HV, tensile strength of more than 440 MPa, and dilution of less than 10 % being the lowest. Microstructural examination confirmed the presence of a strong metallurgical bond at the interface which was marked by the presence of small and compact dendritic structures in the clad area and resistance tests showed that the substrate had a better resistance. The optimized sample was found to have a very good combination of mechanical properties and surface quality, thus the use of RSM as a prediction and optimization tool for GMAW cladding was confirmed. This study sets the groundwork for the design of processes and performance prediction in the field of surface engineering applications involving the use of dissimilar metal cladding.