The effect of severe plastic deformation on the brittle-ductile transition in low carbon steel

Masaki Tanaka, Kenji Higashida, Tomotsugu Shimokawa

    研究成果: 書籍/レポート タイプへの寄稿

    2 被引用数 (Scopus)


    Brittle-ductile transition (BDT) behaviour was investigated in low carbon steel deformed by an accumulative roll-bonding (ARB) process. The temperature dependence of its fracture toughness was measured by conducting four-point bending tests at various temperatures and strain rates. The fracture toughness increased while the BDT temperature decreased in the specimens deformed by the ARB process. Arrhenius plots between the BDT temperatures and the strain rates indicated that the activation energy for the controlling process of the BDT was not changed by the deformation with the ARB process. It was deduced that the decrease in the BDT temperature by grain refining was not due to the increase in the dislocation mobility controlled by short-range barriers. Quasi-three-dimensional simulations of dislocation dynamics, taking into account of crack tip shielding due to dislocations, were performed to investigate the effect of a dislocation source spacing along a crack front on the BDT. The simulation indicated that the BDT temperature is decreased with decreasing in the dislocation source spacing. Molecular dynamics simulations revealed that moving dislocations were impinged against grain boundaries and were reemitted from there with increasing strain. It indicates that grain boundaries can be new sources in ultra-fine grained materials, which increases toughness at low temperatures.

    ホスト出版物のタイトルDuctility of Bulk Nanostructured Materials
    出版社Trans Tech Publications Ltd
    ISBN(印刷版)0878493050, 9780878493050
    出版ステータス出版済み - 1月 1 2010


    名前Materials Science Forum

    !!!All Science Journal Classification (ASJC) codes

    • 材料科学(全般)
    • 凝縮系物理学
    • 材料力学
    • 機械工学


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