Zr-Cr合金的显微组织及腐蚀行为

Microstructure and Corrosion Behavior of Zr-Cr Alloy

以高纯锆为母材,在归一化条件下制备Zr-Cr二元合金,在400℃/10.3 MPa过热蒸汽中进行腐蚀试验。利用扫描电镜(SEM)、透射电镜(TEM)对合金及腐蚀生成氧化膜的显微组织进行研究。结果表明,Zr-Cr合金中只存在细小、呈条带状的密排六方结构Zr Cr2第二相,其数量和条带密度会随着合金中Cr含量的提高而增加,但颗粒尺寸没有明显变化。在高纯锆中添加Cr元素能够改善其在400℃/10.3 MPa过热蒸汽中的耐腐蚀性能。增加Cr含量能够降低Zr-Cr合金腐蚀后氧化膜的缺陷数量,提高氧化膜致密性,从而改善耐腐蚀性能。

Zr-Cr binary alloy was prepared under normalized conditions using high purity zirconium as base material,and corrosion test was carried out in 400 ℃/10. 3 MPa superheated steam. The microstructures of the alloy and the oxide film resulting from corrosion were studied by SEM and TEM. Results showed that Zr-Cr alloys only have the second phase particles（ spps） in hcpZr Cr2 phase,and spps quantity increased with increasing Cr content,but the particle size did not change significantly. The addition of Cr to high purity zirconium could improve the corrosion resistance in 400 ℃/10. 3 MPa superheated steam. Cr element can improve the density of oxide film,thus improving the corrosion resistance.