316L不鏽鋼與600鎳基合金惰氣鎢極電弧異質銲接之特性研究

Abstract

異質金屬銲接因其能結合兩種或多種材料之優點，例如耐高溫、抗腐蝕與高強度，在電力工程、化工製程及航太工業等領域具有關鍵應用價值。本研究選用316L沃斯田體不鏽鋼與Inconel 600鎳基超合金作為異質接合材料，並採用惰性氣體鎢極電弧銲（GTAW）進行實驗，該方法具有高穩定性與良好的熱輸入量控制能力，有助於減少銲道缺陷與熱影響區之不良變化。為提升銲接銲道之機械性質與結構完整性，研究中應用田口實驗法進行參數優化，選定電流、送線速度與銲接速度三項重要製程參數進行實驗規劃與效能評估，並同步進行全因子實驗使其得到更加全面的數據應用，並選用Monel 400作為填充金屬，因其與316L及Inconel 600具有良好的冶金相容性。實驗中藉由拉伸測試、顯微硬度分析與金相組織觀察來評估銲道的力學與結構特性。結果顯示，在85A電流、8 mm/s送線速度與2.5 mm/s銲接速度下，銲道表現出最佳的抗拉強度（527 MPa），且破斷位置多集中於銲道重熔區，顯示銲道品質對整體性能有決定性影響。進一步的顯微組織分析指出，異質銲道中存在明顯的熔合區、熱影響區（HAZ）及晶界變化，且進行電化學腐蝕試驗，得知兩種材料於異質銲接後的抗腐蝕變化。綜合而言，本研究成果有助於釐清316L不鏽鋼與Inconel 600鎳基合金之異質銲接行為，並提供未來於高溫、高腐蝕環境下應用之製程優化依據。Dissimilar metal welding combines the advantages of two or more materials, such as high-temperature resistance, corrosion resistance, and high strength, making it critically important in fields including power engineering, chemical processing, and aerospace industries. In this study, 316L austenitic stainless steel and Inconel 600 nickel-based superalloy were selected as the dissimilar joining materials, and Gas Tungsten Arc Welding (GTAW) was employed due to its high stability and precise heat input control, which help minimize weld defects and undesirable changes in the heat-affected zone (HAZ). To enhance the mechanical properties and structural integrity of the weld, the Taguchi method was applied for parameter optimization, with current, wire feed speed, and welding speed selected as key process parameters. A full factorial experiment was also conducted to obtain more comprehensive data for practical application. Monel 400 was chosen as the filler metal for its good metallurgical compatibility with both 316L and Inconel 600.Mechanical and structural performance of the welds was evaluated through tensile testing, Vickers microhardness analysis, and metallographic examination. Results showed that at 85 A current, 8.0 mm/s wire feed speed, and 2.5 mm/s welding speed, the weld achieved the highest tensile strength (527 MPa), with fracture locations predominantly in the weld remelted zone, indicating the decisive influence of weld quality on overall performance. Microstructural analysis revealed distinct fusion zones, heat-affected zones, and grain boundary variations in the dissimilar welds. Electrochemical corrosion tests further demonstrated changes in corrosion resistance between the two materials after dissimilar welding.Overall, this study provides valuable insights into the welding behavior of 316L stainless steel and Inconel600 nickel-based alloy and offers process optimization references for applications in high-temperature and highly corrosive environments.