內窺鏡施夾器夾鉗對精密度與機械性能具有嚴格要求，實務上多採麻田散鐵不銹鋼（SUS420J2）製造。然而，傳統連續沖壓製程受限於材料高加工硬化率之特性，易導致模具磨損、毛邊過大（最高達 0.068 mm）及工件開裂等缺陷，致使生產不良率高達 8.8%，難以符合醫療器材對產品品質與製程穩定性之嚴格要求。 為突破上述瓶頸，本研究針對傳統沖壓製程與結合鍛造預成形與精密沖壓下料之沖鍛複合製程，進行系統性比較。研究首先透過 Minitab 製程能力分析與金相檢驗評估傳統製程缺陷，確立改善基準；並經球化退火試驗結果，確立780 °C持溫6小時為最佳球化退火條件，以確保材料加工穩定性（硬度控制於 HV 93.7）。在模具設計階段，導入 Deform 3D 有限元素分析（FEA），分析鍛造過程中材料流動行為與最大主應力分布，藉此指導預成形模具之幾何優化，成功降低成形裂縫發生風險。本研究之實驗設計歷經兩階段演進：第一階段試作採用電熱式連續熱風鍛造爐進行熱鍛，卻發現工件表面出現嚴重脫碳現象，且因高溫熱脹冷縮導致重複定位精度不足，造成胚料錯位。經系統性檢討後，第二階段優化實驗改採「真空球化退火、室溫冷鍛預成形、二次球化退火與精密沖壓下料」之全新流程，顯著降低高溫脫碳問題並確保定位精度。最後，針對兩種製程進行等規模之對比實驗，全面評估熱處理後工件之外觀精度、微觀組織與機械性能。 實驗結果顯示，導入沖鍛複合製程後，總不良率由8.8%顯著降低至0.8%，毛邊高度亦由0.068 mm降低至0.013 mm，成功達成醫療客戶對夾鉗零件「無可見毛邊」之品質要求。微觀與巨觀性能分析顯示，沖鍛複合製程所形成之三維壓應力有助於晶粒細化與組織緻密化，使熱處理後工件之推力值較傳統沖壓製程提升39.6%，且300次重複擊發耐久試驗之通過率由90.5%提升至100%。綜合而言，本研究證實沖鍛複合製程可有效提升醫療微型零件之尺寸精度、機械性能與製程穩定性，並建立適用於SUS420J2醫療零件之製程開發流程，可作為醫療器械精密微型零件量產及後續製程設計之重要參考。;Endoscopic clip applier jaws are subject to stringent requirements for dimensional precision and mechanical performance and are commonly manufactured from martensitic stainless steel (SUS420J2). However， owing to the high work-hardening rate of the material， conventional progressive stamping is prone to defects such as die wear， excessive burr formation—with burr heights reaching 0.068 mm—and workpiece cracking. Consequently， the production defect rate can reach 8.8%， making it difficult to meet the stringent product quality and process stability requirements of medical devices. To overcome these limitations， this study systematically compared conventional stamping with a stamping–forging hybrid process integrating forging preforming and precision blanking. First， Minitab process capability analysis and metallographic examination were employed to evaluate defects in the conventional process and establish a baseline for improvement. Spheroidizing annealing experiments identified holding at 780 °C for 6 h as the optimal condition， ensuring stable material formability with the hardness controlled at HV 93.7. During die design， Deform 3D finite element analysis (FEA) was used to investigate material flow behavior and maximum principal stress distribution during forging. The results guided the geometric optimization of the preforming die and successfully reduced the risk of forming cracks. The experimental design evolved through two stages. In the first-stage trial， hot forging was performed using an electrically heated continuous hot-air forging furnace. However， severe surface decarburization was observed， while thermal expansion and contraction at elevated temperatures reduced repeat-positioning accuracy and caused blank misalignment. Following a systematic review， the second-stage optimized experiment adopted a new process comprising vacuum spheroidizing annealing， room-temperature cold-forging preforming， secondary spheroidizing annealing， and precision blanking. This process substantially alleviated high-temperature decarburization and ensured accurate positioning. Finally， comparative experiments of an equivalent scale were conducted for the two processes to comprehensively evaluate the appearance and dimensional accuracy， microstructure， and mechanical properties of the heat-treated workpieces. The experimental results showed that implementing the stamping–forging hybrid process significantly reduced the overall defect rate from 8.8% to 0.8%. The burr height was also reduced from 0.068 mm to 0.013 mm， successfully meeting the medical-device customer’s quality requirement of “no visible burrs” for the jaw components. Microscopic and macroscopic performance analyses indicated that the triaxial compressive stress generated during the hybrid process promoted grain refinement and microstructural densification. Consequently， the thrust force of the heat-treated workpieces increased by 39.6% compared with that of conventionally stamped workpieces， while the pass rate in the 300-cycle repeated-firing durability test improved from 90.5% to 100%. Overall， this study confirms that the stamping–forging hybrid process can effectively enhance the dimensional accuracy， mechanical performance， and process stability of miniature medical components. It also establishes a process development framework for SUS420J2 medical components， providing an important reference for the mass production and future process design of precision miniature medical-device components.
