Microstructure-specific hardening of ferritic-martensitic steels pre and post 15 dpa neutron irradiation at 330 °C: A dislocation dynamics study. (March 2021)

• Record Type: Journal Article
• Authors: Mahler, Michael; Po, Giacomo; Cui, Yinan; Ghoniem, Nasr; Aktaa, Jarir
• Is Part Of: Nuclear materials and energy. Volume 26(2021)
• Publication Date: 2021-03
• Subjects: Dislocation dynamics -- Ferritic-martensitic -- Eurofer -- Irradiation hardening -- Defect interaction; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2020.100814
• Languages: English
• ISSNs: 2352-1791

Abstract

Abstract: In this work, we used Dislocation Dynamics (DD) simulations to investigate the role of the hierarchical defects microstructure of ferritic-martensitic steel Eurofer97 in determining its hardening behavior. A Representative Volume Element (RVE) for DD simulation is identified based on the typical martensitic lath size. Material properties for DD simulations in b.c.c Eurofer97 are determined, including the dislocation mobility parameters. The dependence of material parameters on temperature is fitted to experimental yield strength measurements carried out at room temperature and 330 °C, respectively. Voids and precipitates observed in the microstructure, such as M23 C6 and Tantalum-rich MX, are considered in our DD simulations as inclusions with realistic size distribution and volume density, while 〈1 1 1〉 -and 〈1 0 0〉 -type irradiation loops are included directly in the DD simulations. The lath structure, together with its typical precipitates arrangement and the different crystallographic orientation of the martensitic blocks can also be captured in the simulations. DD simulations are used to extract microstructure-specific hardening parameters, which can be used to simulate the properties of Eurofer97 at the engineering scale.