Effect of dislocation distribution on the yield stress in ferritic steel under identical dislocation density conditions. (1st March 2020)

• Record Type: Journal Article
• Authors: Tanaka, Yuki; Masumura, Takuro; Tsuchiyama, Toshihiro; Takaki, Setsuo
• Is Part Of: Scripta materialia. Number 177(2020)
• Page Start: 176
• Page End: 180
• Publication Date: 2020-03-01
• Subjects: Ferritic steels -- Yielding behavior -- Dislocation distribution -- Dislocation density -- Transmission electron backscatter diffraction; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.10.018
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Yield stresses of ferritic iron pre-deformed at 298 K and 213 K were compared under an identical dislocation density. The specimens pre-deformed at 213 K introduced uniformly distributed dislocations, while those at 298 K formed dislocation cell structure. After the pre-deformation, tensile tests and stress-relaxation tests were performed at room temperature. The specimens with uniformly distributed dislocations exhibited significantly lower yield stress and larger stress-relaxation than those with cell-structured dislocations even under almost same dislocation density. This result suggests that the uniformly distributed dislocations contain a large amount of mobile dislocations which can easily move at a low stress compared with the cell-structured dislocations. Graphical abstract: Image, graphical abstract