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TECHNIQUES FOR INTERGRANULAR CRACK FORMATION AND ASSESSMENT IN ALLOY 600 BASE AND ALLOY 182 WELD METALS

  • LEE, TAE HYUN (Korea Institute of Machinery & Materials (KIMM)) ;
  • HWANG, IL SOON (Department of Nuclear Engineering, Seoul National University) ;
  • KIM, HONG DEOK (Central Research Institute, Korea Hydro and Nuclear Power Co., Ltd.) ;
  • KIM, JI HYUN (School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST))
  • Received : 2014.04.29
  • Accepted : 2014.08.27
  • Published : 2015.02.25

Abstract

Background: A technique developed to produce artificial intergranular stress corrosion cracks in structural components was applied to thick, forged alloy 600 base and alloy 182 weld metals for use in the qualification of nondestructive examination techniques for welded components in nuclear power plants. Methods: An externally controlled procedure was demonstrated to produce intergranular stress corrosion cracks that are comparable to service-induced cracks in both the base and weld metals. During the process of crack generation, an online direct current potential drop method using array probes was used to measure and monitor the sizes and shapes of the cracks. Results: A microstructural characterization of the produced cracks revealed realistic conformation of the crack faces unlike those in machined notches produced by an electrodischarge machine or simple fatigue loading using a universal testing machine. Conclusion: A comparison with a destructive metallographic examination showed that the characteristics, orientations, and sizes of the intergranular cracks produced in this study are highly reproducible.

Acknowledgement

Supported by : Korea Institute of Energy Technology Evaluation and Planning (KETEP)

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