The dynamic behaviour of a twinning induced plasticity steel

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

卷:589

Article

Rahman, K. M.¹  Vorontsov, V. A.¹  Dye, D.¹ 

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

关键词: Twinning;    Mechanical characterisation;    Austenite;    Yield phenomena;    Steel;   

DOI  :  10.1016/j.msea.2013.09.081

来源: Elsevier

【 摘 要 】

The influence of strain rate on the twinning behaviour and microstructure of an Fe-15Mn-2Al-2Si-0.7C twinning induced plasticity (TWIP) steel has been investigated. A Hopkinson pressure bar setup was used in addition to blast testing to perform the high strain rate testing. The yield stress exhibited a positive strain rate sensitivity with increasing strain rate. However, the failure strain of the material was relatively unaffected. Post-deformation microscopy indicated that deformation twinning was less profuse at higher strain rates. Electron backscatter diffraction also indicated the activation of multiple twin systems at strain rates below 1000 s(-1) although this did not occur at the higher strain rates tested. A large intragranular misorientation was found to exist in the material tested at lower strain rates indicating a relatively larger dislocation density existing in the material tested at lower strain rates. In addition selected grains in the blast tested material exhibited a 'wavy' structure which was determined not to be due to a phase transformation. It is suggested that this was caused by the complex loading experienced by the material during testing. High resolution transmission electron microscopy also indicated a large density of intrinsic stacking faults in the material subjected to blast testing. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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