In-situ Characterization of Cast Stainless Steel Microstructures
Cast austenitic stainless steel (CASS) that was commonly used in U.S. nuclear power plants is a coarse-grained, elastically anisotropic material. The engineering properties of CASS made it a material of choice for selected designs of nuclear power reactor systems. However, the fabrication processes result in a variety of coarse-grain microstructures that are difficult to inspect ultrasonically, largely due to detrimental effects of wave interactions with the microstructure. To address the inspection needs, new approaches that are robust to these phenomena are being sought. However, overcoming the deleterious effects of the coarse-grained microstructure on the interrogating ultrasonic beam will require knowledge of the microstructure and the corresponding acoustic properties of the material, for potential optimization of inspection parameters to enhance the probability of detecting flaws. The goal of improving the reliability and effectiveness of ultrasonic inspection of CASS specimens can therefore potentially be achieved by first characterizing the microstructure of the component. The characterization of CASS microstructure must be done in-situ, to enable dynamic selection and optimization of the ultrasonic inspection technique. This paper discusses the application of ultrasonic measurement methods for classifying the microstructure of CASS components, when making measurements from the outside surface of the pipe or component. Results to date demonstrate the potential of ultrasonic and electromagnetic measurements to classify the material type of CASS for two consistent microstructures-equiaxed-grain material and columnar-grain material.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1032702
- Report Number(s):
- PNNL-SA-74943; 401001060; TRN: US1200535
- Resource Relation:
- Conference: Proceedings of the Eighth International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components, September 29-October 1, 2010, Berlin, Germany, 1036-1045
- Country of Publication:
- United States
- Language:
- English
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In-situ Characterization of Cast Stainless Steel Microstructures
Related Subjects
36 MATERIALS SCIENCE
ACOUSTICS
DEFECTS
FABRICATION
MICROSTRUCTURE
NUCLEAR POWER
NUCLEAR POWER PLANTS
OPTIMIZATION
PROBABILITY
RELIABILITY
STAINLESS STEELS
ULTRASONIC WAVES
ultrasonic NDE
in-situl
microstructure characterization
cast austenitic stainless steel
CASS
diffuse ultrasonic fields
ultrasonic attenuation