High temperature strain heterogeneities tracking within hole-specimens of FV566 turbine steel via digital image correlation

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

卷:777

Article

Bao, Jianguang^1,2  Benaarbia, Adil³  Bao, Siyuan⁴  Guo, Xiaofeng¹  Wang, Yonghong⁴  Sun, Wei¹ 

[1] Univ Nottingham, Dept Mech Mat & Mfg Engn, Nottingham NG7 2RD, Notts, England

[2] Aviat Ind Corp China, Aircraft Strength Res Inst, Xian 710065, Shaanxi, Peoples R China

[3] Univ Lorraine, Arts & Met Inst Technol, LEM3, CNRS, F-57000 Metz, France

[4] Hefei Univ Technol, Sch Instrument Sci & Optoelect Engn, Hefei 230009, Anhui, Peoples R China

关键词: High temperatures;    Digital image correlation;    Strain heterogeneities;    FV566 steel;    Finite element analysis;   

DOI  :  10.1016/j.msea.2020.139068

来源: Elsevier

【 摘 要 】

This paper presents experimental and numerical investigations to study spatial-temporal distributions of strain heterogeneities within a FV566 turbine rotor steel subjected to high temperature conditions. Strain field were determined during monotonic tensile tests performed on flat specimens containing a circular hole to give rise to heterogeneous strain fields. A home-made digital image correlation system with an image restoration module was developed and employed to record and analyse the deformation process till the macroscopic fracture of the investigated specimens. Noticeable in-plane strain concentration zones and effects of the sample design were highlighted and deeply examined. Experimental results combined with finite element analyses based on a classical Johnson-Cook model indicated that the hole shape was the important factor affecting the strength and the spatio-temporal distribution of the strain fields. Microstructural investigations were also conducted to characterize and assess the microscale damage features of the FV566 steel. The ruptured area for all the investigated temperature tests revealed ductile rupture behaviour. Changes on grain boundaries and misorientation near strain localized regions were also investigated. It was found that the propagation of cracks surrounding the hole in FV566 specimens was mainly affected by the nucleation and propagation of strain localization zones.

【 授权许可】

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