Shielded Metal Arc Welding (SMAW): Determining the Thermal Fields With FEM and RSM

Shielded metal arc welding (SMAW) is a manual joining process widely utilized today due to its adaptability and portability across various working conditions and environments. In this welding method, metals are joined using a consumable electrode coated with flux. As the electrode melts to form the weld bead, the flux coating also melts, producing a slag layer, gas, and fume in the weld area. By accounting for the formation of this slag layer, it becomes feasible to determine temperature fields more accurately, thereby predicting the thermally affected areas near the weld joint. This study proposes the integration of the Response Surface Method (RSM) and the Finite Element Method (FEM) to forecast temperature fields in SMAW welding processes. The primary aim of combining these methodologies is to minimize the number of experiments and
$FE$
simulations required for determining temperature fields even inside the welded joints when new welding parameters are considered. The research focuses on a double V-groove butt welding joint with sheet thicknesses of 6 mm, incorporating a slag layer, and examining various welding parameters such as groove angle, welding current, and travel speed. The ranges for groove angle, welding current, and travel speed are 0 to
${45^ \circ }$
, 105 to 140 amperes, and 4.16 to
$5.97{{\ mm}}/\text{sec}$
, respectively. Initially, a Box-Behnken Design (BBD) is employed to configure 21 experiments ( 17 for training and 4 for testing) based on the welding parameters under consideration. Both the weld bead and slag layer dimensions are experimentally measured, and regression models are developed using RSM to predict their geometries. Subsequently, a detailed parameterized SMAW FE model is constructed, integrating welding parameters and both geometries determined by the regression models. The parameterized SMAW FE model is validated experimentally using thermocouples, and the proposed method to determine the temperature field is validated with new experiments different from those used in the DoE. The obtained results confirm the validity of the proposed approach.