Residual stress analysis of alloy 600 U-bends, reverse U-bends, and C-rings: Final report

Technical Report · Tue Nov 01 04:00:00 EST 1994

OSTI ID:10105493

Rudd, C O ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States). Materials Research Lab.

Over the last several years, one of the leading causes of alloy 600 steam generator tubing leaks has been the primary-side-initiated, intergranular stress corrosion cracking (IGSCC) in heavily cold-worked regions of the U-bends or tubesheet expansion transitions. Field and laboratory experiences have demonstrated that high residual stresses contribute significantly to the initiation of primary water stress corrosion cracking (PWSCC). EPRI initiated this project to measure and quantify the magnitude of these residual stresses in steam generator tubes as well as in various laboratory tests specimens. the objectives were: To measure the residual stresses in steam generator tube U-bends; To measure residual stresses in reverse U-bend (RUB) specimens as well as residual stresses and X-ray diffraction peak broadening in C-ring specimens used in laboratory tests; and To determine whether residual stress occurs as a result of exposure to steam generator operating temperature. Using an advanced X-ray instrument, investigators measured residual stresses on both the outside diameter (OD) and inside diameter (ID) surfaces and subsurfaces of steam generator U-bends and on the test surfaces of laboratory RUB and C-ring specimens. They measured these residual stresses in the hoop and axial directions and also calculated equivalent stresses. Results are discussed. 25 refs., 92 figs., 6 tabs.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Pennsylvania State Univ., University Park, PA (United States). Materials Research Lab.
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 10105493
• Report Number(s): EPRI-TR--104340; ON: UN95005086
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100
210200
36 MATERIALS SCIENCE
360103
CRACK PROPAGATION
EXPERIMENTAL DATA
INCONEL 600
MECHANICAL PROPERTIES
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED
RESIDUAL STRESSES
SAMPLE PREPARATION
STEAM GENERATORS
STRESS CORROSION
STRESS RELAXATION
TUBES
WATER COOLED REACTORS