Session: MF-06-01 Materials and Technologies for Nuclear Power Plants-1

Paper Number: 122146

122146 - Effect of Tempering Temperature on Fracture Toughness Properties of the Cna Steel 

One of the new reduced-activation ferritic-martensitic (RAFM) steels that has been developed in the US is the Castable Nanostructured Alloy (CNA). This steel aims to overcome some of the limitations of conventional RAFM steels (F82H and EUROFER97), such as their narrow operating temperature window and their reduced strength at high temperatures. The mechanical properties of materials, including fracture toughness, can degrade significantly under the fusion reactor environment. Therefore, it is crucial to evaluate the material fracture toughness accurately to understand how the material behaves for long-term operation of fusion reactors. In this study, we performed Charpy impact testing and Master Curve fracture toughness testing on one CNA steel heat-treated at two different tempering temperatures of 710°C and 750°C. We used standard 10 x 10 x 55 mm³ Charpy V-notch specimens in the Charpy impact testing to obtain a complete impact energy curve. We used 4mm thick miniature compact tensile specimens in Master Curve fracture toughness testing according to the ASTM E1921 standard method. The results showed that the higher tempering temperature resulted in lower ductile-to-brittle transition temperature (DBTT) from Charpy testing and lower Master Curve reference temperature T₀ than the material tempered at lower temperature. We are conducting microstructural characterization to explain the difference in DBTT and T₀.

Presenting Author: Xiang (Frank) Chen Oak Ridge National Laboratory

Presenting Author Biography: Dr. Xiang (Frank) Chen is a research staff member at Oak Ridge National Laboratory. His research interests include the mechanical behavior of structural materials under extreme environments and the correlation of mechanical property and materials microstructure. Frank holds a Ph.D. degree and an M.S. degree in Nuclear Engineering from the University of Illinois at Urbana-Champaign and a B.E. degree in Nuclear Engineering from Shanghai Jiao Tong University.

Authors:

Xiang (Frank) Chen Oak Ridge National Laboratory
Weicheng Zhong Oak Ridge National Laboratory
Ying Yang Oak Ridge National Laboratory
Mikhail Sokolov Oak Ridge National Laboratory
Yutai Katoh Oak Ridge National Laboratory