鎳基超合金與沃斯田鐵型不銹鋼異種金屬接合特性研究

The Characteristics of Dissimilar Welding between Nickle-Base Superalloy and Austenitic Stainless Steel

謝文基(Wun-Ji Hsieh)

指導教授 ： 黃和悅

國立虎尾科技大學/工程學院/材料科學與綠色能源工程研究所/碩士(2013年)

摘要

本研究主要目的是利用氣體鎢極電弧銲之不同銲接電流，探討鎳基718超合金與304不銹鋼異種金屬接合特性。由於熱電流的形成，可能產生磁場造成偏弧現象，使得異種金屬接合之橫截面會是一種非對稱的情況。觀察使用交直流混合電流銲接與脈衝電流銲接的銲道微觀組織可發現，銲道的平均晶粒尺寸皆稍微小於傳統的氣體鎢極電弧銲，同時也觀察到熔融邊界旁的柱狀枝晶也較為細小；在脈衝電流銲接的試片中，可發現熔融面積明顯較另外兩種方式來的大，可能產生更多的枝晶，且在枝晶間可觀察到存在著微量的Laves相。而在交直流電流混合銲接的方式中，相比於脈衝電流銲接或是傳統的氣體鎢極電弧銲接會有更好的機械性質，如拉伸強度、疲勞循環數或硬度等。

關鍵字

異種金屬 ； 銲接參數 ； 機械性質 ； 顯微組織 ； Laves相

並列摘要

The purpose of this research was primarily to evaluate the characteristics for dissimilar metals joints, Inconel 718 superalloy and Type 304 stainless steel, by gas tungsten arc welding with different welding current types. Due to the thermoelectric currents may form, developing magnetic fields likely to cause arc blow, a cross-sectional view of such a dissimilar welded joint was a non-symmetric fusion. Microstructural examination was performed on welds that the average grain size in the alternating current / direct current mixed welding or pulsed current welding samples were slightly small than the conventional gas tungsten arc welding. Columnar dendritic structure refinement in the vicinity of fusion boundaries was also observed. In the case of plus current welding sample, the fusion area was larger than the others could result in more dendritic crystal. Besides, some amount of Laves phase was also found along the interdendritic regions. Alternating current/direct current mixed welding had better mechanical properties compared to the pulsed current welding or conventional gas tungsten arc welding, such as tensile strength, fatigue cycles and hardness.

並列關鍵字

Dissimilar Metal ； Welding Parameter ； Mechanical Property ； Microstructure ； Laves phase

參考文獻

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