J. Mater. Sci. Technol. ›› 2025, Vol. 222: 55-67.DOI: 10.1016/j.jmst.2024.10.009

• Research Article • Previous Articles     Next Articles

Synergistic inhibition to dissolution corrosion by de-twinning and precipitation in alumina-forming austenitic steel exposed to lead-bismuth eutectic with 10-8 wt.% oxygen at 600 °C

Decang Zhanga, Xiaoxin Zhanga,*, Jun Zhanga, Hao Rena, Zhonghui Liaob, Xian Zengb,*, Qingzhi Yana,*   

  1. aInstitute of Nuclear Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    bChina Nuclear Power Technology Research Institute, Shenzhen 518000, China
  • Received:2024-06-20 Revised:2024-09-26 Accepted:2024-10-08 Published:2025-07-01 Online:2024-11-01
  • Contact: * E-mail addresses: zhangxiaoxin2008@126.com (X. Zhang), zeng.xian12@163.com (X. Zeng), qzyan@ustb.edu.cn (Q. Yan) .

Abstract: This work investigated the original microstructure of cold-worked alumina-forming austenitic steel, along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.% oxygen at 600 °C, using solution-annealed steel for comparison. Anomalously, cold-worked steel presented milder corrosion compared to solution-annealed steel, with average corrosion depths of 314.3 and 401.0 µm after 1700 h exposure. Cold working-induced de-twinning transformed the annealing twin boundaries into normal high-angle grain boundaries (NGBs), increasing NGBs proportion from 36% to 89%. The increased NGBs provided more nucleation sites for intergranular barriers composed of alternate NiAl and M23C6 precipitates, thus better obstructing the dissolution attack.

Key words: Alumina-forming austenitic steel, Lead-bismuth eutectic, Dissolution corrosion, De-twinning, Precipitation