| Zirconium and its alloys have excellent nuclear performance determines it’s a large number of applications in nuclear reactor. At the same time, as a kind of clean and sustainable energy which has gradually begun to replace coal, thermal power and other traditional energy and to scale, this makes great importance to the development and research of zirconium alloy. There are mainly two major problems in the application of zirconium alloy as nuclear fuel cladding tube in reactor: the safety, reliability and the life of component. According to the two problems, countries have developed many different series of zirconium alloys from improving its performance. Zr-4 alloy is widely used in the pressurized water reactor as the representative one. Because it is laden with important tasks that prevent nuclear leak and high requirements of nuclear fuel cycle in the new period, there have a lot of research work to Zr-4 tube in order to improve its service performance. M5 alloy is another representative one which is developed by the French Framatone Company. Study found that the addition of Nb elements have great improve corrosion resistance of the zirconium pipe. The alloy composition of M5 is Zr-1Nb-0.125 O. In addition, the main cause of the failure of the cladding tube is hydrogen embrittlement, which show that hydride has great influence to the properties of zirconium alloy.To sum up, this paper have three types experimental materials: Zr-4 tube of recrystallization state; Zr-4 tube of deformation state; M5 tube of recrystallization state. Then can get microstructure, texture and macro texture of the sample and from using metallographic, ECC, EBSD and XRD. Combining with three kinds of sample which have different composition and processing state, than analyzed its differences. In addition, give the three samples hydrogen treatment using the laboratory autoclave hydrogen permeability equipment. And then observe its metallographic structure and analysis the hydride orientation factor. The main conclusions are as following:① Zr-4 sample of recrystallization state have part of recrystallization grain, and some are elongated grains or grew up abnormally, the average grain size is about 7.0 microns. Zr-4 sample of deformation state have grains which be completely elongated and present the fibrous structure; M5 sample of recrystallization state have completely recrystallization grains and owe uniform structure, the average grain size is about 4.7 microns.② Three samples all have typical C-axis bimodal texture, the two kinds of samples of recrystallization state are typical <11-20>//RD annealing silk texture. However, the sample of deformation state is <10-10>//RD texture, and have a higher intensity.③ The texture analysis of the sample with inner, middle, outer three parts shows that they are all typical bimodal texture, which have little difference. The orientation factor of the two recrystallization state samples is larger than that of the deformation one. But according to the degree of recrystallization, orientation factor decreases in turn in the direction of ND.④ The amount of hydrogen permeability of M5 alloy is less than that of Zr-4 alloy under the same condition, however, the amount and the thinkness of hydride have significantly difference. Compared the hydrogen permeability results to the two kinds of state of Zr-4 alloy, it can be seen that the amount and the thickness of hydride are basically the same. The elements in the Zirconium alloy has a certain impact to the hydrogen absorption capacity.⑤ The hydride represents a network shape and a certain direction in the recrystallization samples(both M5 and Zr-4). In the deformation state sample, the hydride orientation is along the circumferential distribution. The orientation factor of the deformation state sample is significantly less than the recrystallization ones in the statistical analysis. Which shows that alloy composition has nothing to do with the hydride orientation, processing state has a certain influence on hydride orientation. |
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