Development of Gd-Si-O dispersed 316L stainless steel for improving neutron shielding performance

• Published in: Nuclear materials and energy 2020-05, Vol.23, p.100739, Article 100739
• Main Authors: Yang, Xinyi, Song, Liangliang, Chang, Bo, Yang, Qi, Mao, Xiaodong, Huang, Qunying
• Format: Article
• Language: English
• Subjects: Gadolinium; Mechanical alloying; Neutron shielding alloy; Precipitation
• ISSN: 2352-1791; 2352-1791
• DOI: 10.1016/j.nme.2020.100739

•A promising method was proposed to achieve integration of structural alloys with good neutron shielding performance.•High content of Gd up to 7.87 wt.% was successfully introduced into 316L stainless steel to achieve good neutron shielding performance.•Gd2O3 dissolved into the matrix during mechanical alloying, and re-precipitated as Gd2SiO5 nano-particles. The low solubility of gadolinium (Gd) limits its application in iron-based neutron shielding alloys. In this study, a high content of Gd up to 7.87 wt.% was added into 316L stainless steel by mechanical alloying (MA) of Gd2O3 with 316L powder. Neutronics calculation results showed that the shielding efficiency of 0.2 mm thick 7.87 wt.% Gd-316L alloy was equivalent to that of 33 mm thick 316L for thermal neutrons. Microstructure analysis indicated that Gd-Si-O particles with an average size of 12.5 nm were uniformly dispersed in the matrix. It revealed that Gd2O3 dissolved into the 316L matrix during MA and re-precipitated at around 780 °C as Gd2SiO5 by XRD and TG-DSC. This study provides a novel Gd-containing alloy designed to achieve integration of structural alloys with good neutron shielding function for future application. [Display omitted]