Ultrastrong nanocrystalline steel with exceptional thermal stability and radiation tolerance

Congcong Du; Shenbao Jin; Yuan Fang; Jin Li; Shenyang Hu; Tingting Yang; Ying Zhang; Jianyu Huang; Gang Sha; Yugang Wang; Zhongxia Shang; Xinghang Zhang; Baoru Sun; Shengwei Xin; Tongde Shen

doi:10.1038/s41467-018-07712-x

Ultrastrong nanocrystalline steel with exceptional thermal stability and radiation tolerance

Nat Commun. 2018 Dec 19;9(1):5389. doi: 10.1038/s41467-018-07712-x.

Authors

Congcong Du¹, Shenbao Jin², Yuan Fang³, Jin Li⁴, Shenyang Hu⁵, Tingting Yang¹, Ying Zhang¹, Jianyu Huang¹, Gang Sha⁶, Yugang Wang⁷, Zhongxia Shang⁴, Xinghang Zhang⁴, Baoru Sun¹, Shengwei Xin¹, Tongde Shen⁸

Affiliations

¹ Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, China.
² Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
³ State Key Laboratory of Nuclear Physics and Technology, Center for Applied Physics and Technology, Peking University, Beijing, 100871, China.
⁴ School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA.
⁵ Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA.
⁶ Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. gang.sha@njust.edu.cn.
⁷ State Key Laboratory of Nuclear Physics and Technology, Center for Applied Physics and Technology, Peking University, Beijing, 100871, China. ygwang@pku.edu.cn.
⁸ Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, China. tdshen@ysu.edu.cn.

Abstract

Nanocrystalline (NC) metals are stronger and more radiation-tolerant than their coarse-grained (CG) counterparts, but they often suffer from poor thermal stability as nanograins coarsen significantly when heated to 0.3 to 0.5 of their melting temperature (T_m). Here, we report an NC austenitic stainless steel (NC-SS) containing 1 at% lanthanum with an average grain size of 45 nm and an ultrahigh yield strength of ~2.5 GPa that exhibits exceptional thermal stability up to 1000 °C (0.75 T_m). In-situ irradiation to 40 dpa at 450 °C and ex-situ irradiation to 108 dpa at 600 °C produce neither significant grain growth nor void swelling, in contrast to significant void swelling of CG-SS at similar doses. This thermal stability is due to segregation of elemental lanthanum and (La, O, Si)-rich nanoprecipitates at grain boundaries. Microstructure dependent cluster dynamics show grain boundary sinks effectively reduce steady-state vacancy concentrations to suppress void swelling upon irradiation.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't