Application of Optimization Techniques in Enhancing the Mechanical Properties of Mild Steel SAE10XX Welds

Abstract

In order to enhance the mechanical properties of steel structures and reduce their frequent failures, there is a need to increase the quality of welded steel joints. Proper monitoring of key welding parameters that affect the welding process can produce quality weldments with good mechanical properties. In this research, the optimization of mechanical properties of welded mild steel SAE10XX joints was carried out using the shielded metal arc welding (SMAW). Three independent variables—welding speed, welding current, and arc voltage—were studied at 3 levels in the Central Composite Design (CCD) of the Response Surface Methodology (RSM) to ascertain their influence on the three responses: tensile strength, impact strength, and hardness. The quadratic model was more suitable to fit the experimental data. The welded joint optimum hardness, tensile strength, and impact strength were obtained as 165.628 BHN, 551.090 N/mm², and 0.90 J/mm², respectively, at a current of 103.396 A, a speed of 246.019 mm/min, and a voltage of 221.696 V. From the analysis of variance (ANOVA) carried out, the models’ R² values were 0.9167, 0.9910, and 0.9962, respectively, for the hardness, tensile strength, and impact strength models, which showed that the models’ ability to predict the mechanical properties in the welding process is high. The resulting weldment exhibits high tensile, hardness, and impact values, indicative of its robustness and suitability for applications requiring resilience.