The present study features analytical and experimental results of optimizing resistance spot welding performed using a pneumatic force system (PFS). The optimization was performed to join SECC-AF (JIS G 3313) galvanized steel material with SPCC-SD low carbon steel. The SECC-AF is an SPCC-SD (JIS G 3141) sheet plate coated with zinc (Zn) with a thickness of about 2.5 microns. The zinc coating on the metal surface causes its weldability to decrease. This study aims to obtain the highest tensile-shear strength test results from the combination of the specified resistance spot welding parameters. The research method used the Taguchi method using four variables and a combination of experimental levels. The experimental levels are 2-levels for the first parameter and 3-levels for other parameters. The Taguchi optimization experimental results achieved the highest tensile-shear strength at 5049.64 N. It properly worked at 22 squeeze time cycles, 25 kA of welding current, and 0.6-second welding time and 12 holding-time cycles. The S/N ratio analysis found that the welding current had the most significant effect, followed by welding time, squeeze time, and holding time. The delta S/N ratio values were 1.05, 0.67, 0.57 and 0.29, respectively.

The present study features analytical and experimental results of optimizing resistance spot welding performed using a pneumatic (electrode) force system (PFS). This optimization was carried out to incorporate the galvanized steel sheet material SECC-AF (JIS G 3313) and SPCC-SD (JIS 3141) sheet plate coated with zinc with a thickness of about 2.5 microns. The zinc coating on the metal surface causes its weldability to decrease. This study aims to obtain the highest tensile shear strength test results from the combination of the specified resistance spot welding parameters. The research method used the Taguchi method using four variables and a combination of experimental tingkats. This study's experimental tingkat is two tingkats in the first parameter and three tingkats in other parameters. Taguchi optimization results show that the highest tensile shear strength test obtained is 5049.64 N. This was achieved at 22 cycles of squeeze time, 25 kA of welding current, and 0,6-second welding-time, and 12 cycles of holding-time. The S / N ratio analysis found that the welding time had the most significant effect, followed by welding current, holding time, and squeeze time. The delta S / N ratio values were 0.62, 0,41, 0.34 and 0.07, respectively.

This article present the optimization work describes out to joint the dissimilar galvanized steel of SECC-AF (JIS G 3313) and SGCC (JIS G 3302) material. A zinc coating on the surfaces of the galvanized steel sheets will decrease the weldability characteristic of the material. This study used dissimilar galvanised steel sheets to obtain the highest tensile shear strength from the specified resistance spot welding. This research used the Taguchi method with 4-variables and mixed-experimental levels. The mixed-experimental level, namely 2-experimental levels for the first variable and 3-experimental levels for other variables. The highest tensile shear strength was achieved in 5282.13 N. This condition is achieved at a squeezed time of 20 cycles, 27 kA-welding currents, welding time of 0.5 seconds, and holding time of 18 cycles. The S/N ratio analysis has shown the welding current had the most significant effect, followed by welding time, squeeze time, and holding time. The delta values of S/N ratio were 0.79, 0.64, 0.26 and 0.07, respectively. The ANOVA analysis has shown that the P-value of welding current and welding time is 0.006 (0.6%) and 0.015 (1.5%), respectively. This result is expected for optimizing resistance spot welding quality in other materials or significant aspects.

This article reports on technological mastery assistance in three small metal forming industries in Indonesia. Problems in the blangking and piercing separately process caused increased production time which resulted in inefficiency cost. Therefore, the expert team aided in metal forming technology through participatory action research (PAR) methods and experimental methods through reverse engineering for several products. The PAR method involves optimal contribution and participation from the industry. Assistance in mastering technology in small metal-forming industries reduces the manufacturing process from seven to three stages, increasing efficiency. The press machine's tonnage capacity must balance with the force blanking/piercing requirement. The minimum press machine requirement is 6.7 tons, and based on the availability of existing press machines, the expert team recommends a 20-ton capacity press machine. Total efficiency can be further increased by implementing full progressive die technology by combining piercing, blanking, and bending processes.

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