양극분극시험에 의한 고온부재의 뜨임취화도 평가 = The Evaluation of Temper Embrittlement for High Temperature Structural Components by Anodic Polarization Test

다국어 초록 (Multilingual Abstract)

It has been well recognized that a long term service at elevated temperature of 350~550℃ induces temper embrittlement due to carbide precipitation and/or P, Sb and/or 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 temper embrittlement of heat resisting components to secure the reliable and efficient service condition and to prevent brittle failure in service. However, because fracture tests are limitted in size and number of specirmen obtained from the structural components, nondestructive tests are required. In this study, the optimum electrochemical estimation parameters related to test conditions were investigated and discussed by means of electrochemical polarization test methods(ECPTM) in special corrosive envrionment. The destructive small punch(SP) test was performed in order to establish a reliable and sensitive temper embrittlement evaluation tchnique.