Irradiation-assisted stress corrosion cracking of materials from commercial BWRs: Role of grain-boundary microchemistry
Constant-extension-rate tensile tests and grain-boundary analysis by Auger electron spectroscopy which were conducted on high- and commercial-purity (HP and CP) Type 304 stainless steel (SS) specimens from irradiated boiling-water reactor (BWR) components to determine susceptibility to irradiation-assisted stress corrosion cracking (IASCC) and to identify the mechanisms of intergranular failure. The susceptibility of HP neutron absorber tubes to intergranular stress corrosion cracking (IGSCC) was higher than that of CP absorber tubes or CP control blade sheath. Contrary to previous beliefs, susceptibility to intergranular fracture could not be correlated with radiation-induced segregation of impurities such as Si, P, C, N, or S, but a correlation was obtained with grain-boundary Cr concentration, indicating a role for Cr depletion that promotes IASCC. Detailed analysis of grain-boundary chemistry was conducted on neutron absorber tubes that were fabricated from two similar heats of HP Type 304 SS of virtually identical bulk chemical composition but exhibiting a significant difference in susceptibility to IGSCC for similar fluence. Grain-boundary concentrations of Cr, Ni, Si, P, S, and C in the crack-resistant and susceptible HP heats were virtually identical. However, grain boundaries of the cracking-resistant material contained less N and more B and Li (transmutation product from B) than those of the crack-susceptible material, indicating beneficial effects of low N and high B contents.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10121995
- Report Number(s):
- ANL/ET/CP-80141; CONF-931079-17; ON: DE94006542; TRN: 94:005551
- Resource Relation:
- Conference: 21. water reactor safety information meeting,Bethesda, MD (United States),25-27 Oct 1993; Other Information: PBD: Dec 1993
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of water chemistry on intergranular cracking of irradiated austenitic stainless steels
Effects of water chemistry on itergranular cracking of irradiated austenitic stainless steels
Related Subjects
36 MATERIALS SCIENCE
BWR TYPE REACTORS
REACTOR COMPONENTS
STRESS CORROSION
REACTOR MATERIALS
CRACKS
NEUTRON ABSORBERS
INTERGRANULAR CORROSION
RADIATION EFFECTS
STAINLESS STEELS
210200
360105
360106
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED
CORROSION AND EROSION