Short Intergranular Cracks in Elasto-Plastic Polycrystalline Aggregate

2002 ◽  
Author(s):  
Leon Cizelj ◽  
Heinz Riesch-Oppermann
Keyword(s):  
Grain Size ◽  
Stress Corrosion ◽  
Steam Generator ◽  
Local Stress ◽  
Stress Fields ◽  
Computational Algorithms ◽  
Polycrystalline Aggregate ◽  
Intergranular Stress Corrosion ◽  
Crack Tips ◽  
Steam Generator Tubes

Computational algorithms aiming at modeling and visualization of the initiation and growth of intergranular stress corrosion cracks (e.g., in the steam generator tubes) on the grain-size scale have already been proposed. Main focus of the paper addresses the influence of randomly oriented anisotropic elasto-plastic grains on the microscopic stress fields at crack tips. The limited number of calculations indicate that the incompatibility strains, which develop along the boundaries of randomly oriented grains, influence the local stress fields (J-integrals) at crack tips significantly.

The Geometry of Steam Generator Tube and Its Relevance to the Occurrence of Stress Corrosion Cracking in Operating Nuclear Power Plants

2010 ◽  
Author(s):  
Deok Hyun Lee ◽  
Do Haeng Hur ◽  
Myung Sik Choi ◽  
Kyung Mo Kim ◽  
Jung Ho Han ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Steam Generator ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Corrosion Cracking ◽  
Location Type ◽  
Steam Generator Tubes ◽  
Non Destructive

Occurrences of a stress corrosion cracking in the steam generator tubes of operating nuclear power plants are closely related to the residual stress existing in the local region of a geometric change, that is, expansion transition, u-bend, ding, dent, bulge, etc. Therefore, information on the location, type and quantitative size of a geometric anomaly existing in a tube is a prerequisite to the activity of a non destructive inspection for an alert detection of an earlier crack and the prediction of a further crack evolution [1].

Assessment of primary water stress corrosion cracking of PWR steam generator tubes

1992 ◽  
Vol 134 (2-3) ◽  
pp. 199-215 ◽  
Author(s):  
V.N. Shah ◽  
D.B. Lowenstein ◽  
A.P.L. Turner ◽  
S.R. Ward ◽  
J.A. Gorman ◽  
...  
Keyword(s):  
Water Stress ◽  
Stress Corrosion ◽  
Steam Generator ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Primary Water ◽  
Steam Generator Tubes

Insights into Stress Corrosion Cracking Mechanisms from High-Resolution Measurements of Crack-tip Structures and Compositions

2010 ◽  
Vol 1264 ◽  
Author(s):  
Stephen Michael Bruemmer ◽  
Larry Thomas
Keyword(s):  
High Resolution ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Common Mechanism ◽  
Crack Advance ◽  
Oxidation Reactions ◽  
Intergranular Stress Corrosion ◽  
Cross Sectional ◽  
Crack Tips

AbstractResults are presented employing cross-sectional analytical transmission electron microscopy (ATEM) to examine intergranular stress corrosion cracking (IGSCC) of austenitic stainless alloys in high-temperature water environments. Microstructural, chemical and crystallographic characterization of buried interfaces at near-atomic resolutions is used to investigate corrosion/oxidation reactions, composition changes and deformation events at crack tips. Information obtained by a wide variety of high-resolution imaging and analysis methods indicates the processes occurring during crack advance and provides insights into the mechanisms controlling SCC. Examples of crack tips produced in oxidizing and hydrogenated water are presented for both Fe-base stainless steels (SSs) and Ni-base stainless alloys. Cracks in SSs show similar characteristics in both environments, with oriented oxide films at crack walls and cracks ending in few-nm-wide tips. Many of these same features are seen for alloy 182 in oxidizing water suggesting a common mechanism, generally consistent with a slip oxidation process. A distinct difference is seen at alloy 600 and alloy 182 tips produced in hydrogenated water. Penetrative attack along grain boundaries without evidence for significant plastic deformation is believed to indicate a major role of active-path corrosion/oxidation in the SCC process.

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