## 2 Materials and Methods
### Welding Setup, Parameters, and Quality Assurance  
All welding operations were carried out using a SOYER BMK-16i (Soyer, Wurzbach, Germany) study welding machine equipped with digital process control to ensure precise and repeatable settings. For the SRM (stud welding with radially symmetric magnetic field) process, a PH-3N SRM welding gun (Soyer, Wurzbach, Germany) with integrated shielding \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Test Sample** & **Welding Type** & **Material** & **Operations** & **Stud Specification** \\ \hline
3-3 & Arc with ceramic ferrule & Steel 1.0038 & Plasma cutting, grinding, welding & M12 \(\times\) 30 A2-50 RD + RF 12 (14 pcs) \\
3-5 & ARC CF & Steel 1.4301 & - & M12 \(\times\) 30 A2-50 RD + RF 12 (14 pcs) \\
6-3 & Arc with shielding gas (ARC SG) & Steel 1.0038 & - & M12 \(\times\) 70 A2-50 PD (14 pcs) \\
6-5 & ARC SG & Steel 1.4301 & - & M12 \(\times\) 70 A2-50 PD (14 pcs) \\
9-3 & Arc with SRM (ARC SRM) & Steel 1.0038 & - & M12 \(\times\) 40 A2-50 HZ-1 (14 pcs) \\
9-5 & ARC SRM & Steel 1.4301 & - & M12 \(\times\) 40 A2-50 HZ-1 (14 pcs) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Prepared stud welding samples with corresponding welding method, base material, and sample identifiers used for macrostructural, hardness, and non-destructive testing. \begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**S235 JR + N** & **C** & **Mn** & **Si** & **P** & **S** & **Al** & **Cu** \\ \hline Content of chemical elements, \% & 0.12 & 0.76 & 0.011 & 0.017 & 0.012 & 0.043 & 0.10 \\ - & Cr & Ni & Mo & Ti & V & Nb & N \\ Content of chemical elements, \% & 0.05 & 0.03 & 0.009 & 0.002 & 0.003 & 0.002 & 0.005 \\ \multicolumn{8}{c}{**Mechanical Properties**} \\ Testing temperature & & & 20 \({}^{\circ}\)C & & & & & \\ Yield strength & & & 302 N/mm\({}^{2}\) & & & & \\ Tensile strength & & & 435 N/mm\({}^{2}\) & & & & \\ Elongation & & & 32\% & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Chemical composition and mechanical properties of steel 1.0038 (S235 JR + N) used in this study. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**X5 CrNi218-10** & **C** & **Mn** & **Si** & **P** \\ \hline Content of Chemical elements, \% & 0.027 & 1.7 & 0.310 & 0.032 \\ - & Cr & Ni & S & N \\ Content of chemical elements, \% & 18.14 & 8.06 & 0.001 & 0.076 \\ \multicolumn{8}{c}{**Mechanical Properties**} \\ Testing temperature & & & 20 \({}^{\circ}\)C & \\ Conventional yield Strength for permanent deformation 0.2\% & 311 N/mm\({}^{2}\) & \\ Yield strength & & & 618 N/mm\({}^{2}\) & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Chemical composition and mechanical properties of steel 1.4301 (X5 CrNi218-10) used in this study. gas supply and magnetic field generation was employed. The welding gun and control system were designed to ensure high repeatability and consistent arc formation [20]. Each welding method used standardized studs conforming to EN ISO 13918:2017 [18] and certified in accordance with DIN EN 10204/3.1. For the CF technique, M12 \(\times\) 70 A2-50 RD studs (Bolte, Neumark, Germany) with RF 12 ceramic ferrules were used. The SG method used M12 \(\times\) 70 A2-50 PD studs without aluminum ignition balls, while the SRM process employed M12 \(\times\) 40 A2-50 HZ-1 studs specifically designed for stable arc formation under a magnetic field. For both SG and SRM welding, a shielding gas mixture of 82% CO\({}_{2}\) and 18% Ar was supplied at a flow rate of 4 L/min. Weld positions on each test plate were pre-marked using a 0.5 mm thick laser-cut stainless-steel template to ensure consistent stud spacing and precise alignment. Prior to welding, all plate surfaces were brushed and cleaned with acetone to remove contaminants. According to EN ISO 14555:2017 [15], the essential parameters for achieving a high-quality stud weld include welding current, arc duration, arc voltage, stud lift (initial gap), plunge depth, and, where applicable, shielding gas flow rate and ferrule type.