Thermal-convection-loop corrosion tests of 316SS and IN800 in molten nitrate salts

Technical Report · Mon Feb 01 04:00:00 EST 1982

DOI:https://doi.org/10.2172/5353081· OSTI ID:5353081

Bradshaw, R W

The corrosion behavior of Type 316 stainless steel and Incoloy 800 in molten NaNO/sub 3/-KNO/sub 3/ was studied using thermal convection loops which operated between the temperature limits, 630/sup 0/C to 350/sup 0/C, for up to 4000 hours. Corrosion rates were approximately 1 mil/year (2.5 x 10/sup -2/ mm/year) at 600/sup 0/C for 316SS but increased to about 4 mil/year at 630/sup 0/C. Less extensive results are reported for IN800 but the corrosion rates appear to be similar to 316SS. Corrosion products consisted of the spinels, Fe/sub 3/O/sub 4/ and Fe(Fe,Cr)/sub 2/O/sub 4/, at temperatures below 600/sup 0/C, although NaFeO/sub 2/ and Fe(Fe,Cr)/sub 2/0/sub 4/ were present at higher temperatures. In addition, internal oxide penetration was observed in IN800. Considerable spalling of surface scales was found at temperaturs above 600/sup 0/C and a mass balance was developed to estimate total corrosion rates from weight change and metallographic data. Chromium, but not iron or nickel, accumulated as a solute in the melt as a result of depletion from the alloys, but no thermal gradient mass transfer was detected.

• Research Organization: Sandia National Labs., Livermore, CA (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5353081
• Report Number(s): SAND82-8210; ON: DE82012313
• Country of Publication: United States
• Language: English

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14 SOLAR ENERGY
140700* -- Solar Thermal Power Systems
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMIUM
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
CRYSTAL STRUCTURE
CSP
Concentrating Solar Power
DATA
ELEMENTS
EXPERIMENTAL DATA
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH TEMPERATURE
HOURLY VARIATIONS
INCOLOY 800
INCOLOY ALLOYS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
IRON OXIDES
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MATERIALS
METALS
MICROSTRUCTURE
MINERALS
MOLTEN SALTS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NITRATES
NITRITES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM NITRATES
SALTS
SCALING
SODIUM COMPOUNDS
SODIUM NITRATES
SODIUM OXIDES
SPINELS
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VARIATIONS
WEIGHT