THE DIFFERENCE EFFECT AND ANODIC BEHAVIOR OF HAFNIUM DISSOLVING IN HYDROFLUORIC ACID. Progress Report on CORROSION OF NUCLEAR METALS

Technical Report · Sun Jan 01 04:00:00 EST 1961

OSTI ID:4075092

James, W J; Straumanis, M E; Johnson, J W

Crystal bar hafnium dissolving in HF in the presence of HCl exhibited a positive difference affect similar to that previously observed for zirconium dissolving in HF. The effect was so pronounced that the hydrogen volume developed by the internal polarization current was overbalanced and the rate of self dissolution by an additional 3 mm/sup 3/ cm/sup -2/ min/sup -1/ of hydrogen was reduced. The effect was accompanied by a strong shift of the hafnium electrode toward noble values. Similar potential changes were observed upon the addition of noble metal salts to the acid mixture; the rats of dissolution dropped to zero with Pt/sup 4+/ additions in HF alone but only slightly in HF-HCl. The results of the difference effect studies, together with rate measurements in HF - HCl, appeared to confirm a previous conclusion with regard to ths high rate of dissolution of zirconium: The dissolution rate is brought about by the direct chemical action of molecular HF. Possible explanations are given for the slight increase of metal dissolution in ths presence of HCl additions. (auth)

• Research Organization: Missouri. Univ., Rolla. School of Mines and Metallurgy
• NSA Number: NSA-15-012799
• OSTI ID: 4075092
• Report Number(s): TID-11935
• Country of Publication: United States
• Language: English

Related Subjects

ANODES
BEHAVIOR
CHEMISTRY
CORROSION
CRYSTALS
ELECTRIC POTENTIAL
ELECTRODES
HAFNIUM
HYDROCHLORIC ACID
HYDROFLUORIC ACID
HYDROGEN
IONS
METALS
NOBLE METALS
PLATINUM
POLARIZATION
SALTS
SOLUTIONS
VOLUME
ZIRCONIUM