Micromechanics of twinning in a TWIP steel

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:635

Article

Rahman, K. M.¹  Jones, N. G.²  Dye, D.¹ 

[1] Univ London Imperial Coll Sci Technol & Med, Dept Mat, Royal Sch Mines, London SW7 2BP, England

[2] Univ Cambridge, Dept Mat Sci & Met, Cambridge CB3 0FS, England

关键词: Twinning;    Synchrotron radiation;    Austenitic steel;    Yield phenomena;    Micromechanical modeling;   

DOI  :  10.1016/j.msea.2015.03.082

来源: Elsevier

【 摘 要 】

The deformation behaviour of a TWinning Induced Plasticity (TWIP) steel was studied at quasi-static strain rates using synchrotron X-ray diffraction. A {111} RD and {200} RD texture developed from the earliest stages of deformation, which could be reproduced using an elasto-plastic self consistent (EPSC) model. Evidence is found from multiple sources to suggest that twinning was occurring before macroscopic yielding. This included small deviations in the lattice strains, {111} intensity changes and peak width broadening all occurring below the macroscopic yield point. The accumulation of permanent deformation on sub-yield mechanical cycling of the material was found, which further supports the diffraction data. TEM revealed that fine deformation twins similar to those observed in heavily deformed samples formed during sub-yield cycling. It is concluded that twinning had occurred before macroscopic plastic deformation began, unlike the behaviour traditionally expected from hexagonal metals such as Mg. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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