本實驗採用低碳鋼同質銲接件及經鋁化處理之銲材，於試片表面沉積2 mg / cm2 氯化鈉/硫酸鈉混合鹽層，比較試片沉積和未沉積混合鹽於750 ℃ 固定應力負載下之潛變行為。
　　實驗結果顯示，低碳鋼同質銲接件於熱腐蝕環境中，試片表面因快速生成肥厚的氧化皮膜，阻止脫碳及不正常晶粒成長，使低碳鋼同質銲接件於熱腐蝕環境拉伸壽命較高溫氧化環境增加2小時。試片經熱浸鍍鋁程序後，因鋁塗層在高溫時增加試片抗氧化能力，另一方面，鋁化層在拉伸頸縮時，造成鋁化層向內擠壓，鋁化層硬度較高可減緩頸縮現象延後斷裂時間，於高溫氧化環境拉伸壽命增加17小時。鋁化處理試片於熱腐蝕環境拉伸，受到鋁化層的保護增加抗熱腐蝕能力，使其拉伸壽命和單純高溫氧化環境拉伸，有著近乎相同的拉伸壽命。
關鍵詞：低碳鋼，同質銲接，熱浸鍍鋁，熱腐蝕，潛變。

　　The main objective of the current research was to determine and compare creep resistance of uncoated weldment in a low-carbon steel material with that of an aluminized weldment of a similar low-carbon steel substrate. The experiment was conducted in an environment containing salt solution by depositing about 2 mg/cm2 mixture of NaCl/Na2SO4 at 750 C.
　　The experimental results show that similar welded parts of the low-carbon steel substrate in hot corrosion environment formed a thick oxide film which prevented decarburization and abnormal grain growth. Thus, the low-carbon steel similar welded parts are stretched in hot corrosion environment with two hours higher creep life.
　　After the hot-dip aluminizing process of the low carbon steel similar weldment, the aluminide coating highly improved oxidation resistance of the substrate material at high-temperature exposure. During creep test, aluminized coatings due to its high hardness slowed down the necking phenomenon and therefore delayed the rupture time increasing creep life by 17 hours under high temperature oxidation. The aluminized substrate under creep test in hot corrosion showed similar improvement as that tested in simple high temperature environment.
Key words: Low carbon steel; Similar weldment; Hot dip aluminizing; Hot corrosion; Creep

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