Stress corrosion cracking of alloys 600 and 690 in all-volatile-treated water at elevated temperatures: Final report

Technical Report · Sun May 01 04:00:00 EDT 1988

OSTI ID:5028646

Miglin, B P; Theus, G J

This report describes stress corrosion (SCC) tests of Inconnel alloys 600 and 690 in all-volatile treated (AVT) water. Specimens of alloys 600 and 690 were exposed to AVT water at 288/degree/, 332/degree/, 343/degree/, and 360/degree/C. Alloy 660 generally resists SCC in high-purity water at normal sevice temperatures, but is susceptible to SCC at higher temperatures. In general, mill-annealed alloy 600 is more susceptible than high-treated material with fine lacy grain boundary carbides. Very high stresses (near or above yield) are required to induce cracking of alloy 600 in AVT or other high-purity waters. For alloy 600, 78 of 520 alloy 600 specimens eventually cracked. Although exposed for less total time than alloy 600 specimens, no alloy 690 specimens cracked. Three alloy 600 specimens cracked in the same autoclave tests in less time than those accumulated by the alloy 690 specimens. Longitudinally-oriented ID cracks became evident on alloy 690 split-tube U-bend specimens after autoclave exposures. These cracks on the 690 specimens were from three to ten times longer after exposure than similar defects found on unexposed alloy 690 specimens. The longitudinal crack lengthening on the alloy 690 split-tube U-bend specimens may have been a stress relaxation process or possibly a crack opening process of pre-existing, partially closed, longitudinal defects. Similar cracks were present in alloy 600 specimens, but in at least one case SCC did initiate from these shallow, blunt cracks.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (USA)
• OSTI ID: 5028646
• Report Number(s): EPRI-NP-5761M; ON: TI88010461
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200 -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
BOILERS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COLD WORKING
COMPARATIVE EVALUATIONS
CORROSION
CRACK PROPAGATION
CRACKS
CRYSTAL STRUCTURE
DOCUMENT TYPES
FABRICATION
FEEDWATER
GRAIN BOUNDARIES
HEAT TREATMENTS
HIGH TEMPERATURE
HYDROGEN COMPOUNDS
INCONEL 600
INCONEL 690
INCONEL ALLOYS
IRON ALLOYS
MATERIALS
MATERIALS TESTING
MATERIALS WORKING
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
OXYGEN COMPOUNDS
POWER PLANTS
PROGRESS REPORT
REACTOR MATERIALS
STEAM GENERATORS
STRESSES
TEMPERATURE EFFECTS
TESTING
THERMAL POWER PLANTS
VAPOR GENERATORS
WATER