APPLICATION OF ELECTROLESS-NICKEL BRAZING TO TUBULAR FUEL ELEMENTS FOR THE N.S. SAVANNAH. Status Report

Technical Report · Mon Jun 01 04:00:00 EDT 1959

DOI:https://doi.org/10.2172/4206537· OSTI ID:4206537

Lamartine, J T; Thurber, W C

The feasibility of using electroless nickel, a chemical deposit containing about 10 wt.% phosphorous in nickel, as the brazing alloy for assembling tubular stainless steel fuel elements of the type specified in Core I of the N. S. Savannah was investigated. This material was selected primarily because of the ease of braze-metal preplacement by chemical deposition of the alloy on type 304 stainiess steel ferrule spacers, prior to fuelbundle assembly. Brazed joints produced by this method were generally characterized by a relatively ductile solid-solution region at the thinnest portions of the fillet. This ductile zone should minimize the possibility of complete propagation of hairline cracks, which form in the brittle, eutectic regions of fillet. The microstructural appearance of the electroless-nickel joints was not appreciably affected by variations in the brazing temperature from 1750 to 1900 deg F or the brazing time from 15 to 60 min. Several plating solutions were evaluated and all were found to be capable of producing deposits suitable for brazing applications. Corrosion tests conducted in static 525 deg F water indicated that no significant attack of joints brazed with electroless nickel had occurred after 300-hr exposure. A small fuel bundle was successfully assembled by brazing with electroless nickel. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-13-020148
• OSTI ID: 4206537
• Report Number(s): CF-59-6-55
• Country of Publication: United States
• Language: English

Related Subjects

BOILING
BRAZING
BRITTLENESS
CORROSION
CRACKS
DUCTILITY
EUTECTICS
FUEL ELEMENTS
HIGH TEMPERATURE
JOINTS
MATERIALS TESTING
METALLOGRAPHY
METALLURGY AND CERAMICS
MOTION
NICKEL
PHOSPHORUS
PLATING
SOLID SOLUTIONS
SPACERS
STAINLESS STEELS
TUBES
WATER
ZONES