Mapping of Microscopic Strain Distributions in an Alloy 600 C-Ring After Application of Hoop Stresses and Stress Corrosion Cracking

作者：McIntyre N S^*; Ulaganathan J; Simpson T; Qin J; Sherry N; Bauer M; Carcea A G; Newman R C; Kunz M; Tamura N

来源：Corrosion, 2014, 70(1): 66-73.

DOI：10.5006/1006

• elastic strain
• hoop stress
• Laue diffraction
• plastic strain
• polychromatic x-ray microdiffraction
• stress corrosion cracking

Laue diffraction measurements made using polychromatic synchrotron x-radiation have revealed significant changes to the microscopic strain distributions in an Alloy 600 (UNS N06600) tube following the application of a circumferential (hoop) stress and then as a result of stress corrosion cracking (SCC). The changes in the elastic and plastic strain distributions were studied for the same area near the outer diameter of the tube prepared as a C-ring. Following the application of the circumferential stress, there was a notable loss of crystal order within the outermost 3 mu m to 5 mu m of the tube surface as a result of plastic processes; further into the sample the elastic strains in grain boundaries become oriented toward the direction of the impressed stress. The average intensity of oriented tensile strain is 5x10(-3) within the outermost 50 mu m of the C-ring. After corrosion, the elastic strain distribution in the same region becomes slightly compressive. The strains associated with a network of fine incipient cracks on the outside diameter of the C-ring were explored; elastic compressive strains were found within few micrometers from the crack center presumably as a result of crack opening, while plastic deformation was limited to the immediate crack region.

• 出版日期2014-1