Production of intergranular attack of alloy 600, alloy 690, and alloy 800 tubing in tubesheet crevices: Topical report

Technical Report · Wed Jul 01 04:00:00 EDT 1987

OSTI ID:6129549

Scott, D B

Three model boilers, manufactured to simulate full-size tube sheet crevices, were tested with various secondary side environments. The first was faulted with organics representative of the decomposition of humic acid. The second was faulted with sodium carbonate and sodium hydroxide, while the third was faulted with sodium sulfate and sodium hydroxide. Each model contained seven tubes, which included Alloy 600 in the mill-annealed (MA) and thermally-treated (TT) conditions and Alloy 690 in the thermally-treated condition. Two models contained Alloy 800 tubes in the mill-annealed condition and one had Alloy 800 in the mill-annealed/cold-worked/glass-bead-peened condition. Two different sizes of tubesheet crevices were used in all model boilers. In the organics-faulted boiler, tubes of Alloy 600MA, Alloy 690TT and Alloy 800MA experienced no significant intergranular attack (IGA); however, the Alloy 600TT had intergranular attack (IGA) three to four grains deep. The carbonate-caustic faulted boiler experienced throughwall stress corrosion cracking (SCC) in all tubes of Alloy 600 MA and Alloy 800 MA. Eddy current indications were present in Alloy 690TT, Alloy 600TT and Alloy 800 in the mill-annealed/cold worked/glass-bead-peened condition. Metallographic examination of tubes from the third model boiler, faulted with sodium sulfate and caustic, revealed IGA in the mill-annealed Alloy 600 tubes. The IGA was more extensive in an Alloy 600 tube annealed at 1700/sup 0/F than an Alloy 600 tube annealed at 1875/sup 0/F.

• Research Organization: Combustion Engineering, Inc., Windsor, CT (USA). Nuclear Power Systems; Electric Power Research Inst., Palo Alto, CA (USA)
• OSTI ID: 6129549
• Report Number(s): EPRI-NP-5263; ON: TI87920497
• 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
ALKALI METAL COMPOUNDS
ALLOYS
BOILERS
CARBON COMPOUNDS
CARBONATES
CHEMICAL REACTIONS
CHEMISTRY
CHROMIUM ALLOYS
CORROSION
CRACKS
CREVICE CORROSION
DATA
EXPERIMENTAL DATA
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HUMIC ACIDS
HYDROGEN COMPOUNDS
HYDROXIDES
INCOLOY 800
INCOLOY ALLOYS
INCONEL 600
INCONEL ALLOYS
INFORMATION
INTERGRANULAR CORROSION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POWER PLANTS
SODIUM CARBONATES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SODIUM SULFATES
STEAM GENERATORS
STRESS CORROSION
SULFATES
SULFUR COMPOUNDS
THERMAL POWER PLANTS
TUBES
VAPOR GENERATORS
WATER CHEMISTRY