Insights into the sources of irradiation hardening in a neutron irradiated 304L stainless steel following post-irradiation annealing

JOURNAL OF NUCLEAR MATERIALS

卷:526

Article

Jiao, Z.¹  Hesterberg, J.¹  Was, G. S.¹ 

[1] Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA

关键词: Irradiation hardening;    Dislocation loops;    Solute clusters;    Post-irradiation annealing;   

DOI  :  10.1016/j.jnucmat.2019.151754

来源: Elsevier

【 摘 要 】

The 304L SS was irradiated in Barseback 1 BWR reactor to 5.9 dpa followed by post-irradiation annealing at 500 degrees C and 550 degrees C up to 20 h. Correlations of irradiation hardening with the main hardening features of dislocation loops and Ni/Si-rich clusters were made using the least squares regression. The dispersed-barrier hardening model tended to overestimate the contribution of Ni/Si-rich clusters in the as-irradiated condition. Contribution of Ni/Si-rich clusters to irradiation hardening appeared to be more appropriately accounted for by the short-range order strengthening mechanism and was dependent on the Ni and Si concentrations in the clusters. Irradiation hardening in the as-irradiated condition was predominantly from dislocation loops with minor contribution from the Ni/Si-rich clusters. This is consistent with recent molecular dynamics simulations which showed that Ni/Si-rich clusters were weak obstacles to dislocation glide. As dislocation loops were annihilated at a faster pace than the Ni/Si-rich solute clusters, the Ni/Si-rich clusters played a more important role in the remaining hardening after thermal annealing. Contribution of Ni/Si-rich clusters to remaining hardening outweighed that of dislocation loops after thermal annealing at 550 degrees C for 5 h and became predominant after annealing for 20 h. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

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