Corrosion of high Ni-Cr alloys and Type 304L stainless steel in HNO/sub 3/-HF

Technical Report · Tue Apr 01 00:00:00 EST 1980

DOI:https://doi.org/10.2172/5221375· OSTI ID:5221375

Ondrejcin, R S; McLaughlin, B D

Nineteen alloys were evaluated as possible materials of construction for steam heating coils, the dissolver vessel, and the off-gas system of proposed facilities to process thorium and uranium fuels. Commercially available alloys were found that are satisfactory for all applications. With thorium fuel, which requires HNO/sub 3/-HF for dissolution, the best alloy for service at 130/sup 0/C when complexing agents for fluoride are used is Inconel 690; with no complexing agents at 130/sup 0/C, Inconel 671 is best. At 95/sup 0/C, six other alloys tested would be adequate: Haynes 25, Ferralium, Inconel 625, Type 304L stainless steel, Incoloy 825, and Haynes 20 (in order of decreasing preference); based on composition, six untested alloys would also be adequate. The ions most effective in reducing fluoride corrosion were the complexing agents Zr/sup 4 +/ and Th/sup 4 +/; Al/sup 3 +/ was less effective. With uranium fuel, modestly priced Type 304L stainless steel is adequate. Corrosion will be most severe in HNO/sub 3/-HF used occasionally for flushing and in solutions of HNO/sub 3/ and corrosion products (ferric and dichromate ions). HF corrosion can be minimized by complexing the fluoride ion and by passivation of the steel with strong nitric acid. Corrosion caused by corrosion products can be minimized by operating at lower temperatures.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (United States). Savannah River Lab.
• DOE Contract Number: AC09-76SR00001
• OSTI ID: 5221375
• Report Number(s): DP-1550; TRN: 80-013691
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
HAFNIUM
CORROSIVE EFFECTS
NITRIC ACID
NUCLEAR FUELS
REPROCESSING
STAINLESS STEEL-304L
CORROSION
HASTELLOYS
HAYNES ALLOYS
INCONEL ALLOYS
INCONEL 625
INCONEL 671
INCOLOY ALLOYS
CHROMIUM ALLOYS
COPPER ALLOYS
IRON BASE ALLOYS
MANGANESE ALLOYS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
FUEL CYCLE
THORIUM CYCLE
ALLOYS
CHEMICAL REACTIONS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COBALT ALLOYS
CORROSION RESISTANT ALLOYS
ELEMENTS
ENERGY SOURCES
FUELS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IRON ALLOYS
MATERIALS
METALS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
REACTOR MATERIALS
REFRACTORY METALS
SEPARATION PROCESSES
STAINLESS STEELS
STEELS
TANTALUM ALLOYS
TRANSITION ELEMENTS
TUNGSTEN ALLOYS
360105* - Metals & Alloys- Corrosion & Erosion
050800 - Nuclear Fuels- Spent Fuels Reprocessing