【摘要】 用 SEM 的波谱(WD)分析手段,定性研究了合金元素铌在 Zr-Sn-Nb-Fe 合金中的存在方式及其与中间退火工艺的关系。研究结果表明添加的合金元素铌主要存在于 Laves 相中,并且随中间退火温度升高,第二相中铌含量增加。铌在 α-Zr 中的含量随退火温度升高而降低,可降低至小于 1×10-4,这与二元 Zr-Nb 合金中合金元素铌的固溶度随温度升高而增加明显不同。铌和铁、铬共存于锆合金中时,将与铁、铬一起优先形成沉淀相,导致合金元素主要存在于第二相中,并出现其在 α-Zr 中固溶量随退火温度升高而降低的现象;其原因可归结为随退火温度升高铌扩散能力增加,从而导致在第二相中含量增加。更多还原

【Abstract】 The existing form of alloying element Nb in two kinds of Zr-Sn-Nb-Fe alloys and its dependence on intermediate annealing were qualitatively investigated by means of WD in SEM. It is showed that most parts of Nb in the alloys exits in precipitate, and the content of Nb in precipitate increases with the increase of intermediate annealing temperature, while the content of Nb in α-Zr matrix decreases with the increase of intermediate annealing temperature, the solubility of Nb in matrix can be lowered to less than 1×10-4, this phenomenon is different from binary Zr-Nb alloy. It suggests that Nb precedently diffuses to precipitate and exist in the precipitate when it added in zirconium alloys together with Fe or Cr, which results in abnormal change of solubility of Nb in α-Zr matrix.更多还原