Lattice strain measurements using synchrotron diffraction to calibrate a micromechanical modeling in a ferrite-cementite steel

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

卷:561

Article

Taupin, V.¹  Pesci, R.¹  Berbenni, S.¹  Berveiller, S.¹  Ouahab, R.¹  Bouaziz, O.² 

[1] Univ Lorraine Arts & Metiers ParisTech, CNRS, LEM3, Lab Etude Microstruct & Mecan Mat, F-57045 Metz, France

[2] Arcelor Mittal, Arcelor Res, F-57210 Maizieres Les Metz, France

关键词: Synchrotron radiation;    X-ray diffraction (XRD);    Dislocations;    Carbides;    Micromechanical Modeling;   

DOI  :  10.1016/j.msea.2012.10.086

来源: Elsevier

【 摘 要 】

In situ tensile tests were performed at room temperature on a ferrite-cementite steel specifically designed for this study. The evolution of the average stress in ferrite during loading was analyzed by Xray diffraction. Lattice strain measurements were performed with synchrotron ring diffraction in both ferrite and cementite. These in situ tests were complemented by macroscopic tensile and reversible tensile-compression tests to study the Bauschinger effect. In order to reproduce stresses in ferrite and cementite particles, a recently developed micromechanical Internal Length Mean Field (ILMF) model based on a generalized self-consistent scheme is applied. In this designed ferrite-cementite steel, the third phase of the model represents finite intermediate layers in ferrite due to large geometrically necessary dislocation (GND) densities around cementite particles. The assumed constant thickness of the layers is calibrated thanks to the obtained experimental data. The ILMF model is validated by realistic estimates of the Bauschinger stress and the large difference between mean stresses in ferrite and in cementite phases. This difference cannot be reproduced by classic two-phase homogenization schemes without intermediate GND layers. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

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