Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
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Determination of Knoop Indentation Stress Conversion Factors for Measuring Equibiaxial Residual Stress

인장 및 압축 등방 잔류응력 측정을 위한 누프 압입시험의 응력환산계수 결정

  • Jeong, Min Jae (School of Materials Science & Engineering, Research Center for Energy and Clean Technology, Andong National University) ;
  • Kim, Young-Cheon (School of Materials Science & Engineering, Research Center for Energy and Clean Technology, Andong National University)
  • 정민재 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 김영천 (안동대학교 신소재공학부 청정에너지소재기술연구센터)
  • Received : 2021.12.05
  • Accepted : 2021.12.21
  • Published : 2021.12.31
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Abstract

Instrumented indentation testing has been widely used for residual stress measurement. The Knoop indentation is mainly selected for determining anisotropic mechanical properties and non-equibiaxial residual stress. However, the measurement of equibiaxial stress state and compressive residual stress on a specimen surface using Knoop indentation is neither fully comprehended nor unavailable. In this study, we investigated stress conversion factors for measuring Knoop indentation on equibiaxial stress state through indentation depth using finite element analysis. Knoop indentation was conducted for specimens to determine tensile and compressive equibiaxial residual stress. Both were found to be increased proportionally according to indentation depth. The stress field beneath the indenter during each indentation test was also analyzed. Compressive residual stress suppressed the in-plane expansion of stress field during indentation. In contrast, stress fields beneath the indenter developed diagonally downward for tensile residual stress. Furthermore, differences between trends of stress fields at long and short axes of Knoop indenter were observed due to difference in indenting angles and the projected area of plastic zone that was exposed to residual stress.

Keywords

Acknowledgement

본 논문은 안동대학교 기본연구지원사업에 의하여 연구되었습니다.

References

  1. Jongsoo Kim, Heesan Kim, Effects of Organic Additives on Residual Stress and Surface Roughness of Electroplated Copper for Flexible PCB, Corrosion Science and Technology, 6, 154 (2007). https://www.j-cst.org/opensource/pdfjs/web/pdf_viewer.htm?code=C00060400154
  2. Kang Yong Seok, Lee Kuk Hee, Shin Dong Man, Factors Affecting Stress Corrosion Cracking Susceptibility of Alloy 600 MA Steam Generator Tubes, Corrosion Science and Technology, 20, 22 (2021). Doi: https://doi.org/10.14773/cst.2021.20.1.22
  3. G. S. Schajer, Advances in Hole-Drilling Residual Stress Measurements, Experimental Mechanics, 50, 159, (2010). Doi: https://doi.org/10.1007/s11340-009-9228-7
  4. W. Woo, G. B. An, E. J. Kingston, A. T. DeWald, D. J. Smith, M. R. Hill, Through-thickness distributions of residual stresses in two extreme heat-input thick welds: A neutron diffraction, contour method and deep hole drilling study, Acta Materialia, 61, 3564 (2013). Doi: https://doi.org/10.1016/j.actamat.2013.02.034
  5. W.-D. Choi, D.-S. Gil, S.-G. Lee, Y.-H. Lee, A Study on the Comparative Evaluation of Welding Residual Stresses of Pipes in Power Plants using Saw-cutting and Indentation Methods, Journal of the Korean Society for Nondestructive Testing, 23, 328 (2003).
  6. J. H. Han, J. S. Lee, Y. H. Lee, M. J. Choi, G. J. Lee, K. H, Kim, D. Kwon, Residual Stress Estimation with Identification of Stress Directionality Using Instrumented Indentation Technique, Key Engineering Materials, 345-346, 1125 (2007). Doi: https://doi.org/10.4028/www.scientific.net/KEM.345-346.1125
  7. M.-J. Choi, S.-K. Kang, I. Kang, and D. Kwon, Evaluation of nonequibiaxial residual stress using Knoop indenter, Journal of Materials Research, 27, 121 (2012). Doi: https://doi.org/10.1557/jmr.2011.335
  8. Y.-C. Kim, H.-J. Ahn, D. Kwon, J.-Y. Kim, Modeling and experimental verification for non-equibiaxial residual stress evaluated by Knoop indentations, Metals and Materials International, 22, 12 (2016). Doi: https://doi.org/10.1007/s12540-015-5515-2
  9. W. J. Kim, Y. J. Kim, and Y.-C. Kim, Stress Conversion Factor Penetration Depth of Knoop Indentation for Assessment of Nano Residual Stress, Journal of the Microelectronics and Packaging Society, 26, 95 (2019). Doi: https://doi.org/10.6117/kmeps.2019.26.4.095
  10. Y.-H. Lee and D. Kwon, Estimation of biaxial surface stress by instrumented indentation with sharp indenters, Acta Materialia, 52, 1555 (2004). Doi: https://doi.org/10.1016/j.actamat.2003.12.006