• Title/Summary/Keyword: first peak current density($I_{FP}$)

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A Study on Electrochemical Polarization Test for Embrittlement Damage Evaluation of Aged Cr-Mo Steel (Cr-Mo강 시효재의 취화손상 평가를 위한 전기화학적 분극시험에 관한 연구)

  • Yu, Hyo-Sun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.19 no.6
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    • pp.411-419
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    • 1999
  • It has been well recognized that a long term service at elevated temperature of $350^{\circ}C{\sim}550^{\circ}C$ induces embrittlement damage due to carbide precipitation and/or P, Sb and Sn segregation at grain boundaries and thereby deteriorates the grain boundary strength of heat resisting components in the energy-related plants. Therefore, it is very important to assess quantitatively the extent of embrittlement damage of heat resisting components to secure the reliable and efficient service condition and to prevent brittle failure in service. However, because fracture tests are limited in size and number of specimen obtained from the structural components, nondestructive test method is required. In this study, the optimum electrochemical parameters are investigated and discussed to evaluate nondestructive embrittlement damage for aged 2.25Cr-1Mo steels by means of electrochemical polarization test method (ECPTM) in proper corrosive environment. In addition, the electrochemical test results are compared with embrittlement degree evaluated by semi-nondestructive SP test.

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