Acta Metallurgica Sinica (English Letters)

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Quantification of Compositional and Residual Stress Effects on Lattice Strain in Dual-phase Stainless Steels by Means of Differential Aperture X-ray Micro-diffraction

Nan LI1), Zhinan AN2), Wenjun LIU3),  Yandong WANG4)   

  1. 1)School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
    2)Department of Materials Engineering, the University of Tennessee, Knoxville, TN 37996, USA
    3)Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
    4)Laboratory of Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100081, China
  • Received:2013-05-31 Revised:2013-06-24 Online:2013-12-25 Published:2014-02-28
  • Contact: Yandong WANG
  • Supported by:

    National Science Foundation of China (No. 51231002). The authors would like acknowledge that the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

Abstract:

Residual stress is an important factor for evaluating the deformation and failure of engineering materials. Diffraction-based measurement assumes that the full measured lattice strain tensor contributes to residual stress according to Hooke's Law. The present work focuses on the lattice strain determination of individual grains in a dual-phase stainless steel (DPSS) by means of differential-aperture X-ray micro-diffraction (DAXM). The results show that the residual stress only takes part of the responsibility of the total measured lattice strain. In fact, the compositional variation inside the material was found to cause greater strain gradient in both ferrite (α) and austenite (γ) phases in DPSS. Therefore, quantification of compositional and residual stress effects on lattice strain was conducted in order to evaluate the true residual stress inside engineering materials.

Key words: Differential aperture X-ray mico-diffraction, Lattice strain, Residual stress, Dual-phase stainless steels