BRAZE BONDING STAINLESS-STEEL FUEL ELEMENTS FOR NUCLEAR REACTORS

Journal Article · Mon Jun 01 04:00:00 EDT 1959 · Welding J. (N.Y.)

OSTI ID:4251067

King, P P; McGeary, R K

A technique was developed that utilizes electroless plating of parts with nickel which contains phosphorus. The plating serves as thc brazing alloy at 1850--1900 deg F in a dry-hydrogen atmosphere. Success of the technique depends upon contact of the parts so that phosphorus depletion of the film of braze alloy by diffusion of the phosphorus into the steel is readily attained, thus producing a ductile single-phase bond alloy. Under controlled conditions of joint preparation, erosion of the base metal by the brazing alloy was negligible during brazing cycles of up to 8 hr at 1875 deg F. Optimum bunndle assemblies were produced by brazing for one hour at stronger bundle assemblies because of growth of the braze-bonded region. Parts fit-up was found to be the most critical factor in influencing joint strength and ductility of large multi-tube subassemblies. Brazingfixture design was critical in controlling subassembly fit- up, lateral dimensions and longitudinal straightness. Fuel-element subassemblies up to 95 in. long and 2.743 in. square were brazed with lateral dimensions within plus or minus 0.015 in. of design and longitudinal bowing of less than 0.060 in. Braze-bonding methods using a paste application of Ni-P, Ni-Cr-P, Ni-Si, Ni-Si-P, Ni-Cr-Si, or Ni-Fe-Si-Mo-P were found to give less satisfactory results. The corrosion resistance of these alloys was investigated and only the Ni-Si and Ni- Si-P alloys were unacceptable for high-temperature water service. (auth)

• Research Organization: Westinghouse Electric Corp., Pittsburgh
• NSA Number: NSA-13-015418
• OSTI ID: 4251067
• Journal Information: Welding J. (N.Y.), Journal Name: Welding J. (N.Y.) Vol. Vol: 38
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BONDING
BRAZING
CHROMIUM COMPOUNDS
CORROSION
DIFFUSION
DUCTILITY
EROSION
EXPANSION
FILMS
FUEL ELEMENTS
HIGH TEMPERATURE
HYDROGEN
IRON COMPOUNDS
JOINTS
MECHANICAL STRUCTURES
METALLURGY AND CERAMICS
MOLYBDENUM COMPOUNDS
NICKEL
NICKEL COMPOUNDS
PHASE DIAGRAMS
PHOSPHORUS COMPOUNDS
PLANNING
PLATING
PREPARATION
SILICIDES
STABILITY
STAINLESS STEELS
TUBES
WATER