PITTING OF ALUMINIUM WITH SPECIAL REFERENCE TO PITTING OF HBWR 1st CHARGE FUEL ELEMENTS

Technical Report · Wed Mar 01 04:00:00 EST 1961

OSTI ID:4067517

Videm, K

The canning of the HBWR first charge fuel elements which are made of Al with 0.6% Fe and 0.07% Si, pitted severely during the 5 months of introductory physics experiments, a period during which the D/sub 2/O purification system was not operated. Corrosion experiments were carried out to find the causes for pitting corrosion. Tests at room temperatare of some aluminum alloys showed that no pitting will occur even when the metal is in contact with stainless steel as long as the water is sufficiently pure. Without purification of the water, corrosion products would increase the conductivity considerably and dangerous coupling effects between aluminum and stainless steel might result. Addition of chloride to the corrosive medium was found to increase the pitting corrosion. NaSiO/sub 3/ did not act as an inhibitor for pitting in the environments of the present experiments. Iron contents up to 0.6% in the alloy were found to have minor effect on the susceptibility to pitting, but addition of 1% Ni aggravated the corrosion. Extensive exposure of various aluminum alloys in very pure water above 100 deg C produced pitting only in extreme cases. It was concluded that the pitting of the HBWR fuel elements was caused by coupling effects between aluminum and stainless steel and water with a locally high impurity level. (auth)

• Research Organization: Norway. Institutt for Atomenergi, Kjeller
• NSA Number: NSA-15-019770
• OSTI ID: 4067517
• Report Number(s): KR-8
• Country of Publication: Norway
• Language: English

Related Subjects

ALUMINUM ALLOYS
CHLORIDES
CORROSION
FUEL CANS
FUEL ELEMENTS
HEAVY WATER
IMPURITIES
IRON ALLOYS
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL ALLOYS
SILICIDES
SODIUM SILICATES
STAINLESS STEELS
WATER COOLANT