本論文主要在研究鑄造狀態FeCoNi(Mo,Nb)等莫耳合金之微結構及電化學性質,包括FeCoNiMo、FeCoNiNb、FeCoNiMo0.5Nb0.5三種金屬合金來做研究。結果顯示這三個合金均為兩相的樹枝狀結構,其中FeCoNiMo為FCC及complex cubic結構;FeCoNiMo0.5Nb0.5合金中的主要相是FCC相及HCP相;而FeCoNiNb合金中的主要相是FCC相及ordered FCC結構相。本論文以恆電流/恆電位儀測量金屬合金在1M硫酸溶液、1M氯化鈉溶液、1M硝酸溶液、1M氯化鈉溶液中不同溫度下的極化曲線,來測定其腐蝕電位、腐蝕電流、鈍態區間電位,並與市售304不銹鋼做比較。電化學實驗結果顯示,在不同溫度之除氧1M硫酸溶液、1M氯化鈉溶液、1M硝酸溶液、1M氯化鈉溶液下,三種合金皆會產生鈍態膜,而隨著溫度升高,腐蝕電位Ecorr及腐蝕電流icorr並沒有太大的變化。但是添加Mo而成的FeCoNiMo合金在酸溶液中的耐蝕性變很差。
This thesis studied the microstructures and corrosion behaviors of as-cast FeCoNi(Mo,Nb) alloys, including FeCoNiNb, FeCoNiMo and FeCoNiMo0.5Nb0.5 alloys. All of these alloys had a dual-phased dendritic microstructure. Two phases in cast FeCoNiMo alloy were FCC and complex cubic phases; two phases in FeCoNiMo0.5Nb0.5 alloy were FCC and HCP phases; and two phases in FeCoNiNb alloy were FCC and ordered FCC phases. The polarization curves of the three alloys in 1M deaerated H2SO4, HNO3, HCl and NaCl solutions were also measured. Only adding Mo had no benefit on the alloy, the polarization tests indicated that the corrosion resistance of FeCoNiMo alloy in these acid solutions was worse.