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用非自耗电弧炉熔炼了Fe/Cr比值为1.75和4.50的Zr(Fe,Cr)_2金属间化合物,它们的粉末经500℃、10.3MPa过热蒸汽腐蚀不同时间后,用X射线衍射、电子探针和透射电子显微镜分析了腐蚀后生成物的结构及其形貌,以及成分的重新分布。Fe/Cr比值不同的Zr(Fe,Cr)_2腐蚀后的生成物都相同,但是含Cr高的更不易被腐蚀。腐蚀初期的生成物是立方ZrO_2,并析出α-Fe(Cr),在继续腐蚀时,立方ZrO_2逐渐转变为单斜ZrO_2,α-Fe(Cr)也逐渐被氧化成(Fe,Cr)_3O_4。Fe和Cr在偏聚时,Fe原子的扩散速率比Cr原子快。根据实验结果,讨论了第二相影响Zr-4合金腐蚀性能的原因。
The Zr (Fe, Cr) _2 intermetallic compounds with Fe / Cr ratios of 1.75 and 4.50 were smelted by non-consumable electric arc furnace. The powders were corroded by superheated steam at 500 ℃ and 10.3 MPa for different time. Electron probe and transmission electron microscope were used to analyze the structure, morphology and redistribution of the products. The products after the corrosion of Zr (Fe, Cr) _2 with different Fe / Cr ratios are the same, but the products with high Cr are less likely to be corroded. In the initial stage of corrosion, the cubic ZrO 2 is precipitated and α-Fe (Cr) is precipitated. The cubic ZrO 2 gradually changes to monoclinic ZrO 2 and the α-Fe (Cr) is gradually oxidized to (Fe, Cr) 3 O 4. When Fe and Cr are segregated, Fe atoms diffuse faster than Cr atoms. According to the experimental results, the reasons for the corrosion of Zr-4 alloy by the second phase are discussed.