• Title/Summary/Keyword: 기계적 잔류응력 이완법

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A Study on Mechanical Stress Relleving in a Butt-Welded Pipe (파이프 용접에서 기계적 잔류응력 이완법에 관한 연구)

  • 양영수
    • Journal of Welding and Joining
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    • v.14 no.1
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    • pp.75-81
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    • 1996
  • The heat transfer and thermal stress-distribution were numerically determined by using the finite element method for a butt-welded pipe. A mechanical stress relieving(MSR) treatment which has been frequently used in the fabrication of pressure vessels instead of the post weld heat treatment (PWHT) was also simulated to investigate its effect of reducing the residual stress in the welded zone by a mechanical loading.

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Experimental Study on the Characteristics of Residual Stress in Welds of Duplex Stainless Steel (듀플렉스 스테인리스강 용접부의 잔류응력 특징에 관한 실험적 연구)

  • Jeon, Juntai
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.147-154
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    • 2017
  • Duplex stainless steel finds increasing use as an alternative to austenitic stainless steel, particularly where chloride or sulphide stress corrosion cracking is of primary concern, due to the excellent combination of strength and corrosion resistance. During welding, duplex stainless steel does not create the same magnitude or distribution of weld-induced residual stresses as those in welded austenitic stainless steel due to the different physical and mechanical properties between them. In this work, an experimental study on the residual stresses in butt-welded duplex stainless steel is performed utilizing the layering technique to investigate the characteristics of residual stresses in the weldment.

A Study on the Measurements of Sub-surface Residual Stress in the Field of Linear Stress Gradient (선형구배 응력장에서 표층의 잔류응력 측정에 관한 연구)

  • 최병길;전상윤;이택순
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1632-1642
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    • 1992
  • When a blind hole of small diameter is drilled in the field of residual stress, strain relieved around the hole is function of magnitude of stress, patterns of stress distribution and hole geometry of diameter and depth. Relieved strain coefficients can be calculated from FEM analysis of relieved strain and actual stress. These relieved strain coefficients make it possible to measure residual stress which vary along the depth in the subsurface of stressed material. In this study, the calibration tests of residual stress measurement are carried out by drilling a hole incrementally on the cantilever or on the tensile test bar. Residual stresses can be determined from measured strains around a shallow hole by application of power series method. For the sake of reliable measurement of residual stress, much efforts should be done to measure relieved strains and hole depth more accurately comparing with conventional procedures of gage subject to the external load. Otherwise linear equations converting strains into stresses may yield erratic residual stresses because of ill-conditions of linear equations. With accurate measurements of relieved strains, residual stress even if varying along the depth can be measured. It is also possible to measure residual stress in the thin film of material by drilling a shallow hole.