Experimental Validation of a Numerical Method that Predicts the Size of the Heat Affected Zone. Optimization of the Welding Parameters by the Taguchi's Method

This work outlines the experimental validation of a numerical method which determines the size of the heat affected zone (HAZ) in a low carbon steel plate using the gas metal arc welding technique. The welding parameters match between the experimental and numerical simulations. The later allows the calculation of the weld beads and temperature fields from which the size of the HAZ can be inferred. This size from numerical simulations compares quite well with the experimentally measured HAZ from the metal grain macrostructure. A relationship between the bead size and the thermal energy source parameters, defined by the Goldak's double ellipsoid, is found. Finally, the size of the HAZ is optimized by Taguchi's method, which make use of the signal-to-noise ratio and the analysis of variance to obtain the influence of the parameters on the size of HAZ. The numerical code can be used for other electric arc welding techniques as GTAW or FCAW.