燃料棒电子束环焊缝试样腐蚀后产生蓝色氧化膜环的机理

Mechanism of the Blue Circle Oxide Films Formed on the Fuel Rods Welded by Electron Beam After Corrosion Tests

燃料棒电子束焊接试样腐蚀后,在近环焊缝区会出现蓝色氧化膜环现象。研究了蓝色环氧化膜的 微观结构和形貌,测量了表面膜厚度和成分。用常规腐蚀法、加速腐蚀法和离子注入法研究了蓝色氧化 膜环处的抗腐蚀性能。试验表明:近环焊缝区已形成蓝色环后并不影响该处锆合金在继续腐蚀时的抗 腐蚀性能,也不影响燃料棒整体的抗腐蚀性能。根据实验结果提出了蓝色氧化膜环的产生机理和消除措施,并在大规模生产中得到了验证。

The blue circle oxide films on fuel rods near the welded zone by electron beam welding were formed after corrosion tests. The microstructure, the thickness and the composition of this oxide films were examined and measured. Corrosion tests for samples with a blue circle or after ion injection were further carried out under normal or strict condition. All tests and inspections mentioned above show that the samples with the blue circle have a perfect corrosion performance during further tests. Based on the results, the mechanism of the formation of blue circle oxide films is suggested as well as the remedies, which have been verified during the volume manufacture.