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US 7,887,638 B2Granted
Removal of niobium second phase particle deposits from pickled zirconium-niobium alloys
AssigneeWestinghouse Electric Corp.
InventorsDavid F. McLaughlin, Vanessa R. Youchum
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Abstract
The present invention relates generally to a process and chemical composition for the removal of adherent niobium-rich second-phase particles (SPPs) from pickled niobium-containing zirconium alloys which includes applying to the alloy surface a chemical composition comprising alkaline hydrogen peroxide; an alkali metal meta-silicate; and a magnesium salt.
Claims6
A smut removal composition, consisting of:
- 3 to 30 weight percent of hydrogen peroxide based on a total weight of the composition;
- 2 to 12 weight percent of an alkali metal meta-silicate based on a total weight of the composition;
- 0.2 to 1.0 weight percent of a magnesium salt based on a total weight of the composition;
- a remainder weight percent of water based on a total weight of the composition;
- and
- a pH value in the range of from 10.0 to 10.7.
3 more elements
Dependencies are inferred from the claim text.