新锆合金碘致应力腐蚀性能研究

Study on the Property of Iodine-induced Stress Corrosion Crack of New Zirconium Alloy

研究了再结晶状态的相同成分、不同织构取向的两块新锆合金板材在不同的实验条件下的抗碘致应力腐蚀性能。用直流电位降法动态监测裂纹的长度。并对试样进行了织构的测定、第二相的观察和断口分析。结果表明,在实验条件下,N18-2(L-T)抗碘致应力腐蚀的能力优于N18-1(T-L)。断口形貌表明,在应力腐蚀裂纹的初始扩展阶段,断口沿晶开裂;在裂纹的稳态扩展阶段,以穿晶准解理扩展为主。

The investigation was conducted on two plates of recrystallized new N18 zirconium alloy i.e N18-1 (T-L) and N18-2 (L-T), which were with the same chemistry composition but different texture. In order to study the property of iodine-induced stress corrosion crack of the zirconium alloy plates, the tests were carried out in different test conditions, and dynamic monitor was used to measure the length of stress corrosion crack. The texture, the second phase particles and fractographs were also investigated. Result shows that N18-2 (L-T) has better I-SCC resistance than N18-l(T-L) at the two set of test conditions. In addition, scanning electron microscopy (SEM) observation shows that the cracks are mainly trans-granular and pseudo-cleavage, but at the first stage, the crack is inter-granular.