## 3 Results and Discussions
A third repetition of combination 9 of this test was carried out to verify the reason for this divergence and it was found that the value of the second test was closer to the third, so it is concluded that this will be the most correct value for that combination of parameters. Regarding combination 7, due to failures in the welding process caused by the absence of material at the regions where the cuts were made, it was not possible to obtain the measurement values. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline  & \multicolumn{6}{c}{**Weld Root Penetration**} & \multicolumn{6}{c}{**Weld Bead Width**} \\  & \multicolumn{3}{c}{**Experiment 1**} & \multicolumn{3}{c}{**Experiment 2**} & \multicolumn{3}{c}{**Experiment 1**} & \multicolumn{3}{c}{**Experiment 2**} \\
**Cut** & **1** & **2** & **3** & **1** & **2** & **3** * & **1** & **2** & **3** & **1** & **2** & **3** \\ \hline Mean (mm) & \(-0.02\) & \(0.07\) & \(-0.03\) & \(-0.02\) & \(0.04\) & \(0.08\) & \(0.02\) & \(0.13\) & \(0.20\) & \(0.13\) & \(-0.15\) & \(0.08\) \\ Median (mm) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) \\ Std. Dev. (mm) & \(0.13\) & \(0.38\) & \(0.17\) & \(0.24\) & \(0.34\) & \(0.43\) & \(0.47\) & \(1.38\) & \(0.88\) & \(0.75\) & \(1.10\) & \(0.98\) \\ MAD (mm) & \(0.06\) & \(0.37\) & \(0.14\) & \(0.20\) & \(0.24\) & \(0.10\) & \(0.41\) & \(1.21\) & \(0.41\) & \(0.09\) & \(0.49\) & \(0.74\) \\ Range (mm) & \(0.43\) & \(1.00\) & \(0.50\) & \(0.51\) & \(0.94\) & \(1.25\) & \(1.31\) & \(3.96\) & \(2.81\) & \(2.21\) & \(3.43\) & \(2.61\) \\ IQR (mm) & \(0.14\) & \(0.71\) & \(0.30\) & \(0.44\) & \(0.61\) & \(0.30\) & \(0.85\) & \(2.45\) & \(1.16\) & \(1.09\) & \(1.51\) & \(1.75\) \\ IQR/Median & - & - & - & - & - & - & - & - & - & - & - \\ CQV & \(5.00\) & \(2.86\) & \(-6.56\) & \(-19.67\) & \(4.07\) & \(-2.14\) & \(12.63\) & \(4.61\) & \(1.33\) & \(2.44\) & \(-8.88\) & \(58.33\) \\ \hline \end{tabular}
\end{table} 
Table 5: Summary of the deviation of the two measured features for the 9 specimens against the median value. (*) analysis that does not comply with Gaussian distribution. After acquiring and organizing the results, the Taguchi method was applied. As seen in Table 6, the values obtained from the S/N ratio for the penetration and width of the weld bead in each experiment are presented. Figure 8: Graphic representation of the average values obtained for the width of the weld bead in experiments 1 and 2. Figure 7: Graphic representation of the average values obtained for welding penetration in experiments 1 and 2. The graphical representation of the mean values obtained for the S/N ratio of welding penetration can be seen in Figure 9. It is possible to verify that the combination of parameters that gives the optimum value of weld bead root penetration is a welding voltage of 20.8 V, a travel angle of 36\({}^{\circ}\), and a welding current of 180 A. The values of the S/N ratio were averaged for the different levels established for welding root penetration. Table 7 reveals these mean values as well as the difference between the maximum and minimum values. The total average of the S/N ratio is 8.08 dB. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Test**} & \multicolumn{2}{c}{**S/N (dB)**} & \multicolumn{2}{c}{**S/N (dB)**} \\  & **Weld Root Penetration** & **Welding Bead Width** \\ \hline
1 & 15.45 & 13.17 \\
2 & 14.90 & 9.67 \\
3 & 4.30 & 7.97 \\
4 & 6.56 & 2.43 \\
5 & 9.87 & \(-\)1.71 \\
6 & 8.51 & 16.48 \\
7 & 1.77 & \(-\)13.07 \\
8 & 7.44 & \(-\)6.21 \\
9 & 3.87 & \(-\)10.29 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: S/N ratio (dB) obtained for the penetration and width of the weld bead. Figure 9: S/N ratio vs. parameter levels for weld bead root penetration. The graphic representation of the mean values obtained for the S/N ratio of the weld bead width can be seen in Figure 10. Once again, different mean values are observed for the different levels.