Innovative Approach to Establish Root Causes for Cracking in Aggressive Reactor Environments

Bruemmer, Stephen M. ; Thomas, Larry E. ; Vetrano, John S. ; Simonen, Edward P.

Pacific Northwest National Laboratory (U.S.)

关键词: Crack Propagation;    Corrosion Resistant Alloys;    Water Cooled Reactors;    36 Materials Science;    Mathematical Models;   

DOI  :  10.2172/15020972
RP-ID  :  PNNL-14448
RP-ID  :  AC05-76RL01830
RP-ID  :  15020972

美国|英语

来源: UNT Digital Library

【 摘 要 】

The research focuses on the high-resolution characterization of degradation microstructures and microchemistries in specimens tested under controlled conditions for the environment and for the material where in-service complexities can be minimized. Thermodynamic and kinetic modeling of crack-tip processes is employed to analyze corrosion-induced structures and gain insights into degradation mechanisms. Novel mechanistic ''fingerprinting'' of crack-tip structures is used to isolate causes of environmental cracking in tandem with quantitative measurements of crack growth. Sample preparation methods and advanced analytical techniques are used to characterize corrosion/oxidation reactions and crack-tip structures at near atomic dimensions in order to gain insight into fundamental environmental cracking mechanisms. Reactions at buried interfaces, not accessible by conventional approaches, are being systematically interrogated. Crack-growth experiments in high-temperature water environments are evaluating and isolating the effects of material condition (matrix strength, grain boundary composition and precipitation) on stress corrosion cracking (SCC). The fundamental understanding of crack advance mechanisms will establish the basis to design new corrosion-resistant alloys for current light-water reactors and advanced reactor systems.