A PSO-RSM Hybrid Optimization Approach for Sugar Plant Structure Case study: Mesfin Industrial Engineering

Abstract

The fabrication of sugar plant structures often requires joining dissimilar metals, particularly austenitic stainless steel (SS-304) for corrosion resistance with low carbon mild steel (St-37) for structural support. However, welding this material combination using the submerged arc welding (SAW) process presents significant challenges due to metallurgical incompatibility. These challenges may result in weld defects such as porosity, cracking, and residual stress, which can reduce structural integrity and increasing manufacturing costs. This study addresses this industrial challenge by developing a data-driven optimization framework to improve weld quality and process efficiency. A hybrid optimization approach integrating Response surface methodology (RSM) and particle swarm optimization (PSO) was applied to investigate the influence of three key welding parameters welding current, arc voltage, and travel speed on major weld quality responses, including penetration depth, reinforcement height, bead width, tensile strength, and hardness. The experiments were designed using a Central Composite Design (CCD). Statistical analysis using Analysis of variance (ANOVA) at a 95% confidence level (P < 0.05) produced regression model with a prediction accuracy exceeding 97.6%. Weld quality was evaluated through both destructive tests (tensile, hardness, bend) and non-destructive techniques including visual inspection, Defectometer testing, ultrasonic testing, and finite element method (FEM) analysis. The results indicate that interaction effects, particularly between voltage-speed and current-speed. Have a greater influence on weld quality than individual parameter effects. The PSO algorithm identified an optimal parameter combination of 300 A welding current, 25 V arc voltage, and 300 mm/min travel speed. Under these conditions, the optimized weld produced a penetration depth of 8 mm, reinforcement height of 1.35 mm, bead width of 9.5 mm, tensile strength of 525 Mpa, and hardness of 19.6 HRC. Experimental validation confirmed that the optimized SAW parameters produced defect free welds with improved mechanical properties. The results demonstrate the effectiveness of the hybrid RSM-PSO approach in optimizing dissimilar welding and provides the sugar industry with a reliable and cost-effective alternative full stainless steel fabrication, achieving approximately a 51% reduction in manufacturing cost.