Creep damage is one of the failure mechanism of components in power plants and processing plants. The current conditions of components are needed to ensure safe operation and to extend inspection intervals. Thus it is necessary to develop techniques to assess the current creep damage of components in service. The "Small Punch Test (SPT)" is one of the techniques, which can directly assess the current material properties of components on site. The pioneer work on small punch test in the creep region has been done by European researchers. In 1994, a COPERNICUS project entitled Small Punch Test Method Assessment for the Determination of the Residual Creep Life of Service Exposure Components (Contract: ERB CIPA CT 94 0103) has been set up and was carried out in laboratories in different European countries. Small punch test method has been explored into the creep region to provide material properties for residual life assessment purpose. The history of small punch test at creep region is only six years and lot of work should be carried out further. For instance, it is found that the temperature oscillation gives a strong influence on the test results. Therefore, a better temperature control system should be developed for the creep test. For interpretation of creep test results, present work is based either on the equivalent stresses concept (developed by CESI) or empirical equation, such as modified form of Dorn equation (developed by Parker etc.). Encouraged by the EPRI analytical approach to determine fracture toughness, KIC, a similar analytical approach is proposed by the author. Examples are given by interpretation of the observed creep curves (deflection vs. time) from small punch test published by ENEL and the COPERNICUS project.
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