The BCC FCC hierarchical martensite transformation under dynamic impact in FeMnAlNiTi alloy

Li, C.*; Fang, W.*; Yu, H. Y.*; Peng, T.*; Yao, Z. T.*; Liu, W. G.*; Zhang, X.*; Xu, P. G.; Yin, F.*

Materials Science & Engineering A, 892, p.146096_1 - 146096_11, 2024/02

https://doi.org/10.1016/j.msea.2024.146096

Cryogenic impact fracture behavior of a high-Mn austenitic steel using electron backscatter diffraction and neutron Bragg-edge transmission imaging

Wang, Y. W.*; Wang, H. H.*; Su, Y. H.; Xu, P. G.; Shinohara, Takenao

Materials Science & Engineering A, 887, p.145768_1 - 145768_13, 2023/11

https://doi.org/10.1016/j.msea.2023.145768

Evolution of dislocation structure determined by neutron diffraction line profile analysis during tensile deformation in quenched and tempered martensitic steels

Dannoshita, Hiroyuki*; Hasegawa, Hiroshi*; Higuchi, Sho*; Matsuda, Hiroshi*; Gong, W.; Kawasaki, Takuro; Harjo, S.; Umezawa, Osamu*

Materials Science & Engineering A, 854, p.143795_1 - 143795_12, 2022/09

https://doi.org/10.1016/j.msea.2022.143795

Age-hardening mechanisms of heterogeneous-nanostructured SUS316LN stainless steel fabricated by heavy cold rolling

Miura, Hiromi*; Watanabe, Chihiro*; Aoyagi, Yoshiteru*; Oba, Yojiro; Kobayashi, Masakazu*; Yoshinaga, Naoki*

Materials Science & Engineering A, 833, p.142531_1 - 142531_12, 2022/01

https://doi.org/10.1016/j.msea.2021.142531

Initial sintering kinetics of non-stoichiometric CeO

Watanabe, Masashi; Seki, Takayuki*

Materials Science & Engineering B, 272, p.115369_1 - 115369_6, 2021/10

https://doi.org/10.1016/j.mseb.2021.115369

The effect of oxygen non-stoichiometry on the initial sintering behavior of CeO was investigated. It was found that the initial sintering of the stoichiometric and hypo-stoichiometric composition was controlled by the grain boundary diffusion. The activation energies of cation diffusion were derived from initial sintering data. Moreover, it is suggested that the cation diffusion was caused by a vacancy mechanism.

Work hardening behavior of dual phase copper-iron alloy at low temperature

Yamashita, Takayuki*; Koga, Norimitsu*; Kawasaki, Takuro; Morooka, Satoshi; Tomono, Shohei*; Umezawa, Osamu*; Harjo, S.

Materials Science & Engineering A, 819, p.141509_1 - 141509_10, 2021/07

https://doi.org/10.1016/j.msea.2021.141509

Solid-solution strengthening by Al and Cr in FeCrAl oxide-dispersion-strengthened alloys

Ukai, Shigeharu*; Yano, Yasuhide; Inoue, Toshihiko; Sowa, Takashi*

Materials Science & Engineering A, 812, p.141076_1 - 141076_11, 2021/04

https://doi.org/10.1016/j.msea.2021.141076

FeCrAl oxide dispersion strengthened alloys are promising materials for accident tolerant fuels for light water reactors (LWRs). In these alloys, Al and Cr are key elements with important synergistic effects: enhancement of the formation of oxidation-resistant AlO phase by Cr addition and suppression of the formation of the embrittling Cr-rich ' phase by Al addition. The solid-solution strengthening resulting from Al and Cr co-addition was investigated in this study. The solid-solution strengthening resulting from Al and Cr co-addition was investigated in this study. The Al and Cr contents were systematically varied from 9-16 at.% and 10-17 at.%, respectively, and tensile tests were conducted at 298 K, 573 K and 973 K in the as-annealed condition. The solid solution strengthening increased linearly, 20 MPa per 1 at.% Al and 5 MPa per 1 at.% Cr, at the typical LWR operational temperature of 573 K. The conventional Fleischer-Friedel and Labusch theories cannot explain this level of solid-solution strengthening. It was shown that Suzuki's double kink theory for screw dislocations reasonably predicts the solid solution strengthening by Al and Cr as well as the inverse dependency on the absolute temperature and linear dependency on the Al and Cr content.

Comparison of dislocation density, twin fault probability, and stacking fault energy between CrCoNi and CrCoNiFe medium entropy alloys deformed at 293 and 140K

Woo, W.*; Naeem, M.*; Jeong, J.-S.*; Lee, C.-M.*; Harjo, S.; Kawasaki, Takuro; He, H.*; Wang, X.-L.*

Materials Science & Engineering A, 781, p.139224_1 - 139224_7, 2020/04

https://doi.org/10.1016/j.msea.2020.139224

Microstructure and texture evolution and ring-tensile properties of recrystallized FeCrAl ODS cladding tubes

Aghamiri, S. M. S.*; Sowa, Takashi*; Ukai, Shigeharu*; Ono, Naoko*; Sakamoto, Kan*; Yamashita, Shinichiro

Materials Science & Engineering A, 771, p.138636_1 - 138636_12, 2020/01

https://doi.org/10.1016/j.msea.2019.138636

Oxide dispersion strengthened (ODS) FeCrAl ferritic steels are being developed as potential accident tolerance fuel cladding materials for the light water reactors (LWRs) due to significant improvement in steam oxidation by alumina forming scale and good mechanical properties up to high temperatures. In this study, the microstructural characteristics and tensile properties of the two FeCrAl ODS cladding tubes with different extrusion temperatures of 1100C and 1150C were investigated during processing conditions. While the hot extruded sample showed micron sized elongated grains with strong -fiber in 110 texture, cold pilger rolling process change the microstructure to submicron/micron size grain structure along with texture evolution to both -fiber (110 texture) and -fiber ({111} texture) via crystalline rotations. Subsequently, final annealing resulted in evolution of microstructure to large grain recrystallized structure starting at recrystallization temperature of 810-850C. Two distinct texture development happened in recrystallized cladding tubes, i.e., only large elongated grains of (110) 211 texture following extrusion temperature of 1100C; and two texture components of (110) 211 and {111} 112 following higher extrusion temperature of 1150C. The different texture development and retarding of recrystallization progress in 1100C-extruded cladding tubes were attributed to higher distribution of oxide particles.

Dislocation densities and intergranular stresses of plastically deformed austenitic steels

Tomota, Yo*; Ojima, Mayumi*; Harjo, S.; Gong, W.*; Sato, Shigeo*; Ungr, T.*

Materials Science & Engineering A, 743, p.32 - 39, 2019/01

https://doi.org/10.1016/j.msea.2018.09.052