Journal of Nuclear Materials最新文献

In order to investigate the effect of microstructure variation induced by processing on corrosion behavior of zirconium alloys, Zr-Sn-Nb alloy original plates were processed by rolling and annealing, and the microstructure and corrosion behavior of both original plates and processed plates were analyzed. It was found that after the original plates were processed, the recrystallized microstructure in original plates was transformed to stress-relieved microstructure in processed plates, with second phase particles ripening. When exposed to pure water and water containing H₃BO₃ and LiOH, the original plates have better corrosion property than the processed plates, and the corrosion transition of the processed plates happened earlier than that of the original plates. The grain structure differences of original plates and processed plates have two aspects of influence on oxide cracking and corrosion transition. Firstly, there were more defects in processed plates which results in smaller grains and larger grain boundary areas in oxide. Secondly, the strength of processed plates is higher, and this will lead to less stress accommodation of the growing oxide by plastic deformation of the matrix, and higher stress in oxide layer formed during the corrosion process. Both factors caused more cracks in the oxide layer of processed plates, leading to earlier corrosion transition and decreasing corrosion property. Second phase particles and their surroundings are susceptible to cracks during corrosion process, and may become the original source of cracks. However, second phase particle ripening was not closely related to decreasing corrosion property of processed plates.

This study investigates the interfacial evolution of Cr/Mo-coated Zr alloys near the Mo-Zr eutectoid temperature, from the viewpoints of microstructure and chemical composition and with the joint application of XRD, TEM and EDS analyses. The experimental findings highlight significant changes in microstructure and diffusion behavior associated with the Mo-Zr eutectoid reaction. In the as-fabricated specimen, it is noted that introducing a Mo-intermediate layer results in the formation of an amorphous Cr layer at the Cr/Mo interface. In the case of the annealing temperature below the Mo-Zr eutectoid reaction, Mo interlayer effectively impedes the diffusion between Cr and Zr, thereby suppressing the formation of intermetallic compounds. However, the diffusion barrier function of Mo interlayer deteriorates when the temperature exceeds the eutectoid point, with the presence of four distinct diffusion zones, including α-Zr, β-Zr, the intermetallic compound Zr(Mo,Cr,Fe)₂, and the Mo layer containing fine Zr(Mo,Cr,Fe)₂ particles. These findings underscore the critical role of Mo-interlayer in influencing the structural stability and intermetallic compound formation in Cr/Mo-coated Zr alloys, not only at the temperature regime around the eutectic reaction, but also at the temperature regime around the eutectoid reaction, which is of great necessity for the practical applications of accident tolerant fuel cladding under high temperature environment.

We investigated the microstructure, mechanical properties, and stress corrosion cracking (SCC) propagation behaviour of 316LN austenitic stainless steel with various cold work (CW) levels. CW increased the crack growth rate of 316LN. The stress corrosion crack growth rate (SCCGR) for 316LN with 5% CW was approximately 6.52% higher than that of the solution-annealed state; 10%, 20%, and 30% CW resulted in 1.20, 3.18, and 6.10 times higher SCCGRs, respectively. A larger residual strain and proliferation of slip bands via cold deformation augmented the SCCGR. The SCC propagation mechanism of 316LN changed with increasing CW levels owing to slip bands.