本研究選擇電極夾持力、點銲電流、點銲時間及保持時間等交流點銲製程 參數，先以田口實驗探討此參數對316L 不銹鋼接頭拉剪負荷影響，接續針對 點銲電流進行品質提升實驗獲致最大接頭拉剪負荷，最後探討最佳化參數組合 對316L 不銹鋼銲核冶金性質影響。實驗結果顯示點銲電流對接頭拉剪負荷最 具顯著影響性。本研究依田口實驗獲致之最佳化參數組合具95%信賴水準。品 質提升實驗獲致之接頭拉剪負荷較田口實驗提高12.85%。綜合田口實驗與品 質提升實驗得知當採用3 kN 電極夾持力、7.3 kA 點銲電流、15 cycles 電極擠 壓時間、15 cycles 點銲時間及7 cycles 保持時間等製程參數時，將獲致316L 不銹鋼交流點銲最大接頭拉剪負荷。另因316L 不銹鋼銲核存在肥粒鐵，故 可獲較母材高之硬度值。

This study employed the Taguchi experiment to investigate the influence of process parameters (electrode force, welding current, welding time, and hold time) of alternating current (AC) spot welding on the tensile-shear load of the 316L stainless steel joint. A quality improvement experiment assisted by welding current was used to determine an optimal process parameter for increasing the tensile-shear load of the joint. The influences of an optimal process parameter on the metallurgical properties of the 316L stainless steel nugget were also investigated. The results show that welding current has the greatest influence on the joint tensile-shear load. According to Taguchi method statistics, an optimal combination of design parameters shows a 95% confidence level. Comparison of results obtained by using the Taguchi experiment, the quality improvement experiment can result in a 12.85% increase in the joint tensile-shear load. Based on the results of this study, an optimal parameter combination of 3 kN electrode force, 7.3 kA welding current, 15 cycles squeeze time, 15 cycles welding time, and 7 cycles hold time give the highest joint tensileshear load for AC spot welding of 316L stainless steel. Compared with the 316L stainless steel base metal, the nugget exhibits delta ferrite in an austenite matrix, resulting in a higher hardness.