【摘要】 <正> 用电化学方法分离出锆-4合金中第二相,研究了不同热处理制度对第二相结构和成分的影响。锆-4合金经1050℃β相加热空冷后,析出的第二相为立方结构的Zr（Fe,Cr）₂,Fe/Cr比值在2.1～2.5之间。试样重新在600～800℃下加热3h,晶体结构不发生改变,只是Fe/Cr比值逐渐降至1.9;但在700～800℃下加热后,有少量的六方结构Zr（Fe,Cr）₂第更多还原

【Abstract】 The effect of heat treatments on the structure and composition of second phase particles (SPPs) in Zircaloy-4 was investigated after SPPs separated from alpha zirconium matrix. After specimens air cooling from heating at 1050C beta phase, the SPPs precipitated during cooling are Zr (Fe, Cr)2 with cubic structure, Fe/Cr ratio in Zr (Fe,Cr)2 is fluctuated between 2. 1-2. 5. The cubic crystal structure does not change but only the Fe/Cr ratio decreases gradually to 1- 9 when specimens were reheated at 600~800C for 3 h. Small amount of precipitates with hexagonal Zr (Fe, Cr)2 can be detected when specimens were reheated at 700~800C for 3 h. SPPs in Zircaloy-4 plates purchased from factory are hexagonal Zr (Fe, Cr)2 with Fe/Cr ratio decreasing from 1. 9 to 1-5, when specimens were reheated at 700~800"C for 3 h. It shows that the Fe and Cr atoms in SPPs will diffuse and substitute with those in surrounding matrix, when specimens were heated at a certain temperature. The solid solution content of Cr atoms in hexagonal Zr (Fe, Cr)2 is higher than that in cubic Zr (Fe, Cr)2, and the diffusion rate of Fe atoms is faster than that of Cr atoms. This is the reason that the Fe/Cr ratio of Zr (Fe, Cr)2 SPPs varies with the difference of heat treatments.更多还原